Penang Computing

Computing and Networking

2006-12-31T22:33:00.000-08:00

Blogs
Multimedia/Computing/Electronic/Jokes & Stories/Health Tips Center /Online Business Tips /Interesting Researches /Missing People/Anti Crime Methods/They Need Helps

Contents
Computer Systems and Operation /Lab Tutorial
Data Communication /Data Communication Lab
Business Data Communications
OPNET IT Guru Simulation Lab Exercises
Visual Basic Tutorial

Yahoo Groups
csc187
csc328

click to earn

Term Papers

Computer System and Operations

2006-12-30T21:20:00.000-08:00

Introduction to computer technology
General definiton of a computer system. Human socialogical need for information. Precise Definition of a digital binary computer.Technological basis for such computers. Introduction to personal computers. An introduction to number systems.Binary, Hexadeicamal. Real Numbers for science& Engineering. BCD (Binary Coded Decimal) for Business & Management.

System software diagram. Software Packeages,Language, Utilities. The operating system. DOS as a file manager. BIOS as an input/output manager. I/O device drivers. Memory managers. Job schedulers. System hardware diagram. The microprocessor. System Bus : Address Bus, Data Bus, Control Bus, Power Bus. User RAM. Video RAM. Disk Systems: Interface, Printers. Serial Interface, Modems, LANs : Servers, workstations. WAN.

Brief History of actual N-bit microprocessors.Architecture of an actual microprocessor. Register Sets: Data Registers, Pointer and Index Registers, Segment Registers, Insctructions. Pointer, Conrol Flags. Machine Instruction by Category. Assembling and running a simple given program. Modifying the given program for user-friendliness. Using the Linker and Debugger. Writing own simple assembler programs. Countdown Looping : Printing a Pascal Language compatible Character-string. Conditional Looping : Printing a C Language-compatible Character-String. Assembler Subroutines and Macros.Creating, Managing and Linking Object-code Library Modules. MASM and Linker, MASM, TASM, NASM tutorial, The art of Assembly Language

Control Design. User Dos in detail. Configuring DOS. File specification. Subdirectories. Influence of Unix: Standard I/O, Pipes, Redirection, Filter. DOS commands. Third Party Utilities. Inside DOS Technical Information. DOS structure: Boot Record, ROM BIOS Interface, DOS program File. Installing Device Drivers. Extended Screen and Keyboard Control.File Management Notes. DOS Disk Allocation. DOS interrupts and Function Calls. DOS control Blocks and work Areas. Hard Disk Information. EXE file structure.

Memory Organisation
DOS Memory Mangement: Conventional, Extended, Expanded Memory. Real Memory. Virtual Memory Segmented Virtual Memory Exampe : Intel's 80286. Paged Segmented. Virtual Memory Example : Intel's 80386. Memory Protection. Multitasking. Tasks and TSSs(Task Stake Segments). Task Switching. Task Linking. Task Nesting. Exceptions and Interrupts: Faults, Traps, Aborts. The Double Fault. Intterupt Descriptor Table. Transparency of Interrupts. Interrupts Examples. Coprocessing and Multiprocessing. Sychronistion: Semphores and Locks.

System Organisation
System Memory Map. I/O Address Map. Hardware Interrupt Listing. The System Bus. Keyboared Scan codes. Adapter Cards. Printer and display technologies. System Intergration.ROM BIOS Program. Interrupts Location. Stack. Data Areas.POST (Power on Self test). Bootstrap Loader. I/O support: Keyboard, Diskette, Printer, Display, Serial Communication. System Configuration Sensing: Memory Size and Equipment Available Time of Day support.Print Screen Support.

Brief Overview of New System Developments
New Computer System and Busses: The ISA ( the formalised 16-bit AT industry Standard Architecture), EISA (32-bit Multi Channel Architecture). New Operations Systems. Windows, DOS 6, OS/2. Alternative Microprocessor, Computer Systems and Busses. Motorola's 68000 to 68040 Apple's Macintosh. Apple's NuBus. RISC Technology by Sun MIPS, Hewlett Packared Unix by UI (Unix International) and the OSF (open software foundation), X-windows vs Motif, etc. LANS, WANs, Networking, Systems Integrations, Open Systems, Cooperative Computing.

Reference
Intel Microprocessor Hardware, Assembly Language

What Is a MAC Address?

2006-03-16T19:30:00.004-08:00

The MAC address is a unique value associated with a network adapter. MAC addresses are also known as hardware addresses or physical addresses. They uniquely identify an adapter on a LAN.

MAC addresses are 12-digit hexadecimal numbers (48 bits in length). By convention, MAC addresses are usually written in one of the following two formats:
MM:MM:MM:SS:SS:SS
MM-MM-MM-SS-SS-SSThe first half of a MAC address contains the ID number of the adapter manufacturer. These IDs are regulated by an Internet standards body (see sidebar). The second half of a MAC address represents the serial number assigned to the adapter by the manufacturer. In the example,
00:A0:C9:14:C8:29The prefix
00A0C9indicates the manufacturer is Intel Corporation.

Why MAC Addresses?
Recall that TCP/IP and other mainstream networking architectures generally adopt the OSI model. In this model, network functionality is subdivided into layers. MAC addresses function at the data link layer (layer 2 in the OSI model). They allow computers to uniquely identify themselves on a network at this relatively low level.

MAC vs. IP AddressingWhereas MAC addressing works at the data link layer, IP addressing functions at the network layer (layer 3). It's a slight oversimplification, but one can think of IP addressing as supporting the software implementation and MAC addresses as supporting the hardware implementation of the network stack. The MAC address generally remains fixed and follows the network device, but the IP address changes as the network device moves from one network to another.

IP networks maintain a mapping between the IP address of a device and its MAC address. This mapping is known as the ARP cache or ARP table. ARP, the Address Resolution Protocol, supports the logic for obtaining this mapping and keeping the cache up to date.
DHCP also usually relies on MAC addresses to manage the unique assignment of IP addresses to devices.

http://compnetworking.about.com/od/networkprotocolsip/l/aa062202a.htm

What Is a MAC Address?

2006-03-16T19:30:00.003-08:00

What Is a MAC Address?

2006-03-16T19:30:00.002-08:00

What Is a MAC Address?

2006-03-16T19:30:00.001-08:00

The MAC address is a unique value associated with a network adapter. MAC addresses are also known as hardware addresses or physical addresses. They uniquely identify an adapter on a LAN.
MAC addresses are 12-digit hexadecimal numbers (48 bits in length). By convention, MAC addresses are usually written in one of the following two formats:
MM:MM:MM:SS:SS:SS
MM-MM-MM-SS-SS-SSThe first half of a MAC address contains the ID number of the adapter manufacturer. These IDs are regulated by an Internet standards body (see sidebar). The second half of a MAC address represents the serial number assigned to the adapter by the manufacturer. In the example,
00:A0:C9:14:C8:29The prefix
00A0C9indicates the manufacturer is Intel Corporation.

Why MAC Addresses?
Recall that TCP/IP and other mainstream networking architectures generally adopt the OSI model. In this model, network functionality is subdivided into layers. MAC addresses function at the data link layer (layer 2 in the OSI model). They allow computers to uniquely identify themselves on a network at this relatively low level.

MAC vs. IP AddressingWhereas MAC addressing works at the data link layer, IP addressing functions at the network layer (layer 3). It's a slight oversimplification, but one can think of IP addressing as supporting the software implementation and MAC addresses as supporting the hardware implementation of the network stack. The MAC address generally remains fixed and follows the network device, but the IP address changes as the network device moves from one network to another.

IP networks maintain a mapping between the IP address of a device and its MAC address. This mapping is known as the ARP cache or ARP table. ARP, the Address Resolution Protocol, supports the logic for obtaining this mapping and keeping the cache up to date.
DHCP also usually relies on MAC addresses to manage the unique assignment of IP addresses to devices.

http://compnetworking.about.com/od/networkprotocolsip/l/aa062202a.htm

What Is a MAC Address?

2006-03-16T19:30:00.000-08:00

The MAC address is a unique value associated with a network adapter. MAC addresses are also known as hardware addresses or physical addresses. They uniquely identify an adapter on a LAN.
MAC addresses are 12-digit hexadecimal numbers (48 bits in length). By convention, MAC addresses are usually written in one of the following two formats:
MM:MM:MM:SS:SS:SS
MM-MM-MM-SS-SS-SSThe first half of a MAC address contains the ID number of the adapter manufacturer. These IDs are regulated by an Internet standards body (see sidebar). The second half of a MAC address represents the serial number assigned to the adapter by the manufacturer. In the example,
00:A0:C9:14:C8:29The prefix
00A0C9indicates the manufacturer is Intel Corporation.

Why MAC Addresses?
Recall that TCP/IP and other mainstream networking architectures generally adopt the OSI model. In this model, network functionality is subdivided into layers. MAC addresses function at the data link layer (layer 2 in the OSI model). They allow computers to uniquely identify themselves on a network at this relatively low level.

MAC vs. IP AddressingWhereas MAC addressing works at the data link layer, IP addressing functions at the network layer (layer 3). It's a slight oversimplification, but one can think of IP addressing as supporting the software implementation and MAC addresses as supporting the hardware implementation of the network stack. The MAC address generally remains fixed and follows the network device, but the IP address changes as the network device moves from one network to another.

IP networks maintain a mapping between the IP address of a device and its MAC address. This mapping is known as the ARP cache or ARP table. ARP, the Address Resolution Protocol, supports the logic for obtaining this mapping and keeping the cache up to date.
DHCP also usually relies on MAC addresses to manage the unique assignment of IP addresses to devices.

http://compnetworking.about.com/od/networkprotocolsip/l/aa062202a.htm

The Assemblers (MASM, MASM611 & TASM3.0)

2005-10-07T00:09:00.000-07:00

The old MASM vs the new MASM 6.11 or TASM 3.0
The Physics computers should have both the old and new versions of the Microsoft Macro Assembler, MASM 4.00 and MASM 6.11. (Other versions were buggy and short-lived.) While MASM 4 and its associated programs DEBUG, LINK etc. are far easier to learn and work with, they are no longer available from commercial suppliers. MASM 6 and Borland's TASM 3 are very similar to each other, but both are more difficult to learn. MASM 4 worked directly under MSDOS, while MASM 6/TASM create their own "integrated development environment" (IDE), which consists of text windows (rather than the graphics windows of Windows 3.1 or Windows 95). Note that, although the latter two use windows, they are not really Windows programs; i. e., they run under DOS. Thus, managing the IDE windows generated by MASM 6 or TASM must be learned. To keep things simple, we will discuss the Microsoft version, whose main component programs are called PWB (Programmer's WorkBench), MASM, ML, LINK and NMAKE. TASM is very similar, and if anything, more user-friendly and easier to learn.
Concerning windows management under the IDE, note in particular:
the close button is on the top left like a Macintosh, not the top right as in Windows,
the minimize button is a down-arrow in the top right corner. Since there is no taskbar, the minimization iconizes the window and places the icon under all other windows.
the maximize button is the up-arrow, top right.
the resize control is the bottom right, as expected
note the Windows menu item. Cascading or tiling the windows makes it easier to move from one to the other. This is especially important in a heavy debugging session when you may have many windows open simultaneously.
Getting Started
MASM 4.00
Type in your program using any editor that can produce clean ASCII text, with no embedded control codes other than the usual , , (tab), etc. I like to use the old Turbo C editor.
To assemble and link a program under MASM 4, at the DOS prompt, you would enter the following commands [" fname" is the root filename of fname.asm; any other extension is illegal]
masm fname,,; [produces .obj, .lst (listing) files]
link fname,,; [produces .exe program file, runnable with command "fname"]
debug fname.exe [to run the program under DEBUG]
MASM 6 or TASM
Exit Windows (the MSDOS PROMPT is usually OK) and enter the directory MASM611 (cd \masm611).
Run an autoexec.bat file which will include paths to the directories under MASM611. Also include the command set help=C:\MASM611\HELP.
cd \MASM611\bin (move to the folder containing pwb.exe, ml.exe, etc.)
Enter pwb (runs Programmers WorkBench, generating the Integrated Development Environment, IDE)
File:Open fname.asm
Project:Compile fname.asm (runs ml.exe, the assembler)
Project:Build fname.asm (runs the linker, generating the .exe file, but no listing)
Run:Execute fname.asm or if there is a problem
Run:Debug fname.asm

HINT#1: some versions of MASM 6 will install themselves with two binary directories under the folder MASM, namely BIN and BINR. They will not create a separate file for your programs, and they will frequently lose their PATH environment variables and fail to find some of their working components such as LINK or NMAKE. I recommend you move the contents of BINR into BIN, remove the now-empty BINR folder, and create a folder where you will keep all your work (I call mine FILES). The FILES folder (or whatever you call it) should be kept backed up on floppy disk. Then if you have to re-install MASM, you can easily restore your original situation. Note also that by keeping your work separate from the other directories, it is easy to see if you have successfully created a .exe program with your last assemble. When your programs are mixed in with MASM's .exe files, they can be hard to find. Don't forget to change your PATH environment variable to reflect these changes.

HINT#2: When you first run PWB, make a new file and immediately save it in your files directory under MASM\FILES\asst1.asm. If you do this consistently, PWB will save its status files (CURRENT.STS and PWBnnnn, where nnnn is a string of 4 or 5 digits) in a consistent location. The loss or perversion of these ancillary files is one of the main reasons PWB fails to work properly.

Use the template below as a first step.
Hello World!
The following tiny program can be used as a template if the code between .STARTUP and .EXIT is replaced by your program. The upper case words are assembler directives, instructions to the assembler to tell it how to form the final product. They will be discussed below. For now, start PWB, use the menu item FILE:NEW and type in the following program:
.MODEL smallDOSSEG.STACK 1000h .DATAmsg db 0DH,0AH,'Hello World!',0dh,0ah,'$'.CODEmain proc .STARTUPdspmsg: ;display message with the following instructions ... mov ah,9 ;prepare for function 9 of interrupt 21 lea dx,msg ;point to the message at msg in the data segment int 21h ;do it.EXITmain endp END
Discussion
Assembler Directives
The upper case words are directives to the assembler. They are sometimes called pseudo-operations or pseudo-ops in some books. Note that DOSSEG and END do not have a preceding dot (I don't know why). This style of using capital letters for assembler directives has become conventional. It serves to make the directives stand out from the rest of the program. MASM converts all lowercase to uppercase, so capitalization is only cosmetic. Note also that the two ways of specifying carriage return/line feed pairs under the .DATA heading are equivalent. [Also legal are 0Dh and 0dH (for carriage return characters).] Your text should have a thorough discussion of assembler directives, but the ones used here should suffice for most situations.
Now the lines "main proc" and "main endp" delineate a procedure's beginning and end. They are pseudo-ops, but are not capitalised. I don't know why, but it seems to be the convention. I suggest you follow it. This program has only one procedure, and its name is "main". Unlike C, however, "main" is not a reserved word, and it could have been called something else (e.g. hello proc and hello endp).
Labels
The word following .STARTUP, dspmsg: is a label. A label is a word starting in column one and followed by a colon (:). A program uses labels to generate addresses. There are no cases of branching or jumping instructions in Hello World!, but if one wished to jump to a particular location in the code, such as the code following dspmsg, one would use the instruction jmp dspmsg. The assembler would calculate the number of bytes that must be added (or subtracted) from the current instruction pointer (IP) and change the IP so that the CPU would continue processing at the new location (at the address of dspmsg).
Comments
Whenever the assembler is parsing (interpreting the code) and it hits a semi-colon (;) it stops and moves to the next line. A comment is there for the reader, and it in no way slows the assembler, because it is ignored after the parsing of the single character ";". It is therefore wise to use comments freely, BUT commenting upon the obvious detracts from the professional mien of a program. In this example, there are really more comments than necessary, but I consider them acceptable in this situation, where pedagogy is the point.
Note that the semicolon applies for only one line. If a comment extends beyond one line, a semicolon must be inserted as the first character of the next line. If it is desired to write a short paragraph of comments, as in explaining how to use a program to the reader of the source code, there is an assembler directive which blocks out a section as a comment so that no semicolons are required. If the assembler sees the word "comment" at the beginning of a line, it will note the next (non-white-space) character, and ignore everything until it hits that character a second time. Thus
comment /This is a comment that could be many lines long .../
uses the slash as the delineating character.
Debugging Your Code
Under MSDOS, DEBUG.COM or DEBUG.EXE was found in either the root directory or the same directory as MASM.EXE. Under Windows 95, it is found in the Windows\Command folder, along with deltree, diskcopy, edit and other important MSDOS utilities. Different versions have slight variations in the command syntax. After typing debug, type a question mark ("?") to obtain a list of commands.
The modern equivalent of DEBUG is called CODEVIEW, which runs under the Integrated Development Environment (IDE). As explained earlier, one enters the IDE by initially running PWB in the MSDOS environment. CODEVIEW is "forked" (loaded and run as a shell under the IDE) when you run your program either (a) under the menu item RUN:DEBUG or (b) if you click on the option after "building" the program (PROGRAM:BUILD ALL). If you are using Windows '95, you can create a "shortcut" (an alias icon) which will automatically exit Windows and start PWB.EXE from within DOS 7.0 (use the right mouse button after selecting pwb.exe from within Windows).
When the linker creates the final product (the .exe file), it has two options:
create a "release" version which is a binary program that will run on its own in an MSDOS environment, or
create a "debug" version which has extra hooks to enable CODEVIEW to display all segments associated with the program, including values of variables, the data area, addresses of variables, etc.
These choices can be set under the menu item OPTIONS:LINK OPTIONS to either debug or release by clicking the radio buttons at mid-screen. Choose the debug option if you wish to step slowly through your program, examining registers and memory contents after each instruction.
Note the difference between the two function keys at the bottom of your screen in CODEVIEW. Step will take you through a procedure call or interrupt as a single instruction, without your having to trace your way through the long and detailed BIOS or DOS interrupts instructions. Use trace to follow the main program through your procedure calls, but once the procedures are debugged, then use the step to "step" (skip) over them next time.
Use the Windows menu item to decide which windows you need to display. Size them (lower right corner) to make best use of your screen. The registers, for example might best be a tall narrow window off to the right, while the source code and memory windows need to be wide and can be only a few lines long. Note the output window which takes over the screen, but returns you to the debugger when you touch a key. The other buttons at the bottom are either self-explanatory, or easily understood by clicking on them (or using the key combinations).

http://physics.concordia.ca/~eddy/391/Chap3.html

MASM611 Readme File

2005-10-03T18:07:00.000-07:00

README.TXT File
Release Notes for the Microsoft(R) MASM Professional Development System, Version 6.11
(C) Copyright 1993, Microsoft Corporation. All rights reserved. This document contains release notes for the Microsoft MASM Professional Development System, version 6.11. The information in this document and in the Microsoft Advisor (online help) is more up-to-date than that in the manuals.

The printed documentation for MASM 6.11 has not changed from MASM 6.1. The MASM 6.11 installation disks provide several important files that include new or updated information for this release. They are:
README.TXT =====> Contains documentation errata, system requirements, information and tips on using MASM 6.11, and known assembler bugs.
PENTIUM.TXT ====> Contains .586 and .586P directives information, descriptions of the new Intel(R) Pentium(TM) instructions, and a table of Pentium timings for all instructions.
CV.TXT =========> Contains release notes for Microsoft CodeView(TM).
ERRMSG.TXT =====> Contains updated information on 32-bit Linker errors, ML error messages, and Microsoft DOSXNT MS-DOS Extender error messages.
SAMPLES.TXT ====> Contains information about MASM samples for MS-DOS and Microsoft Windows 3.1.
NTSAMPLE.TXT ===> Contains information about MASM samples for Microsoft Windows NT.
SUPPORT.TXT ====> Contains updated Microsoft Product Support policies.
======================<>=====================
Part 1: Documentation Errata ----------------------------
Part 2: System Requirements ---------------------------
Part 3: Tips for Using MASM 6.1x -------------------------------- - ALIAS directive - Assembling Files Generated by Compiler - Building 32-Bit Applications - 32-Bit Linking - GROUP Directive and Flat-Model Programming - Structure Packing Issues for Mixed Language Programming - /WIN32 Switch for H2INC - CD-ROM Not a Valid Target - CMP Instruction Encoding - Debugging MASM Applications under Visual C++, 32-Bit Edition, or Fortran PowerStation, 32-Bit Edition - .FPO Directive - INVOKE Command - LINK and System Resources - MOUSE.COM - MS-DOS and Windows NT File Compatibility - Multi-File Assembly with MASM.EXE - NMAKE and NMAKER - Response Files - SAMPLES.TXT and NTSAMPLE.TXT - Using Control-C to Halt Operation of MASM - Using MASM 6.x Structures - Visual C++ 1.0/Fortran PowerStation 1.0 Compatibility - Working with MASM 5.1 Code - Working With Microsoft BASIC Far Strings
Part 4: Known Assembler Bugs ---------------------------- - Exiting from MS-DOS Critical Errors - Expression Order in High-Level Conditionals - Hexadecimal Constants - Initializing Nested Structures - Intersegment Near Jumps in Flat Model - Span-Dependent Expressions used in Macros - Span-Dependent Equates in Macros and EXTERNDEF ABS - Span-Dependent Text Equates - STRUCT and RECORD Initialization - Using The /link /nologo Command Line Options

====================<>=======================
Environment and Tools, Page xxiii: Microsoft Support Services ------------------------------------------------------------- Microsoft Support Services information has been updated. See SUPPORT.TXT, in the directory in which you installed MASM, for the most current Microsoft support information and policies. Environment and Tools, Page 582: LIB Command Line Sample -------------------------------------------------------- The following example, as it appears on page 582, is incorrect:
LIB FIRST +SECOND, , THIRD
It should instead read:
LIB THIRD +FIRST +SECOND
Environment and Tools, Page 649, 651: _syscall and __syscall ------------------------------------------------------------ The H2INC documentation on pages 649 and 651 lists _syscall and __syscall as C keywords recognized by H2INC. These are not recognized, and should be removed.
Environment and Tools, Page 819: Error Message A2156 ---------------------------------------------------- The value range given for the first parameter of the PAGE directive is incorrect; "...either 0 or a value in the range of 10-255" should read "...either 0 or a value in the range of 14-255." Reference, Page 12: ML Command-line Options /Cu and /Cx ------------------------------------------------------- /Cu is not the default command-line option, but is indicated as such in the MASM 6.1 Reference. Instead, /Cx should be indicated as the default. Reference, Page 98: LEA is no longer optimized ---------------------------------------------- The MASM 6.1 Reference indicates that the LEA instruction is encoded as a MOV when the source operand is a direct memory address.
In response to programmer requests, MASM 6.1x no longer performs this optimization automatically. The optimization can be performed by using the OPATTR operator, as shown in the following macro:
MOVLEA MACRO Dest, Symbol IF (OPATTR(Symbol)) AND 08h MOV Dest, OFFSET Symbol ELSE LEA Dest, Symbol ENDIF ENDM
Programmer's Guide, Page 156: Using an Emulator Library ------------------------------------------------------- The sample code demonstrating floating-point instructions served by an emulator contains the directive .STARTUP. This directive should be removed.
Programmer's Guide, Page 202: User-Defined Epilogues & Prologues ---------------------------------------------------------------- The documentation for user-defined epilogue and prologue code reads "Your macro function must return the parmbytes parameter." It should read "...the localbytes parameter."
Programmer's Guide, Page 323: The C++/MASM Interface ---------------------------------------------------- The second sentence in the third paragraph reads: "The linkage specification applies only to called routines, not to external variables." It should read "The linkage specification applies to called routines and external variables." The last sentence in the same paragraph should be removed. Help for Runtime Error R6921 ---------------------------- The online help for runtime error R6921 reads "...Possibly the CONFIG.SYS file contained a line such as DEVICE=C:\OS\MM386.EXE..." The file name should read "C:\DOS\EMM386.EXE".
=================<>=================
The following are system requirements for Microsoft MASM 6.11:
- Personal computer using a 386 or higher processor running MS-DOS version 3.3 or later, Windows version 3.1 or later, or Windows NT version 3.1 or later. - 4 MB of available memory. - Hard disk with 10 MB available space. - One 3.5" high-density (1.44 MB) disk drive (3.5" low-density (720K) or 5.25" high-density (1.2 MB) disks available separately with coupon enclosed).
To target Windows 3.1, you need one of the following:
- Microsoft Windows Software Development Kit (SDK) 3.1. - Microsoft Visual C++ Development System, Standard or Professional Edition.
To target Windows NT, you need one of the following:
- Microsoft Windows NT Software Development Kit (SDK). - Microsoft Visual C++ Development System, 32-Bit Edition.

====================<>=================== ALIAS directive --------------- The ALIAS directive is not included in the printed documentation for MASM 6.11. The ALIAS directive can be used for creating libraries that allow the linker (LINK) to map an old function to a new function.
Syntax: ALIAS =
where alias is the alternate or alias name, and actual-name is the actual name of the function or procedure. The angle brackets are required.
The ALIAS directive should be used with LINK 5.3 or later and LIB 3.2 or later. At this time, ALIAS functions only with the 16-bit linker.
Assembling Files Generated by Compilers ------------------------------------------ Many compilers support assembly-language output. If you experience difficulty assembling the output of such compilers, you may need to assemble using the /Zm option. In some cases (for instance, if the compiler inserts nondelimited comments or page numbers) it may be necessary to edit the assembly-language output by hand.
Building 32-bit Applications ---------------------------- Following are a number of items you should keep in mind when building 32-bit applications with MASM 6.11. Examples of how to create 32-bit applications can be found in the \SAMPLES\NTSAMPLE subdirectory of the directory in which you installed MASM.
32-bit Linking -------------- When you are creating a 32-bit application, you must link separately with a 32-bit linker. To prepare your object files for 32-bit linking, assemble using the following switches: - /c (assembles without linking) - /coff (causes object files to be created in Windows NT- compatible common object file format) After assembling, link with your 32-bit linker. Refer to the documentation included with your particular 32-bit linker for specific information and instructions. In addition, the sample NT applications in \SAMPLES\NTSAMPLE demonstrate the use of /c, /coff, and a 32-bit linker.
GROUP Directive and Flat-Model Programming ------------------------------------------ The GROUP directive has no effect when used in 32-bit flat-model programming. It is recommended that you not use the GROUP directive when programming in flat model.
Structure Packing Issues for Mixed Language Programming ------------------------------------------------------- Microsoft MASM uses /Zp1 as it's default setting for structure packing; this means that structures are not packed. Other languages may use other default settings for packing. For example, Microsoft C/C++ compilers prior to Visual C++ 32-bit edition use /Zp2; Visual C++ 32-bit edition uses /Zp8 as the default. Modules built using different structure packing may not be able to share structure data items, so care must be taken when using structures in mixed language programs.
The packing size is a maximum, not a fixed, packing value. This means that a member must have a size equal to or larger than the packing limit before any packing is done. In many cases, using /Zp4 on assembly modules will allow them to work with other modules compiled with /Zp8 if none of the members have a size larger than 4 bytes. Doubles, long doubles, and member structures larger than 4 bytes will cause problems. If a structure contains members larger than 4 bytes you will need to pack the structure yourself by adding "dummy" data items.
/WIN32 Switch for H2INC ----------------------- Use the /WIN32 switch with H2INC to convert C header files to NT-compatible MASM include files. When you use the /WIN32 switch, C int data types are converted to the 4-byte assembler equivalent DWORD (signed int data types are converted to SDWORD). Without the /WIN32 switch, H2INC converts int data types to 2-byte WORD (and signed int data types to SWORD).
CD-ROM Not a Valid Target ------------------------- A CD-ROM drive is not a valid installation target for MASM 6.11.
CMP Instruction Encoding ------------------------ MASM 6.1x uses a different encoding for the CMP , instruction than MASM 6.0 did. There is no difference in length or processor timing.
Debugging MASM Applications under Visual C++, 32-bit Edition, or Fortran PowerStation, 32-bit Edition ------------------------------------------------------------- When debugging a pure MASM application under the 32-bit editions of Visual C++ or Fortran PowerStation, you must link in the library file (.LIB) provided with these high-level languages (LIBC.LIB in Visual C++, LIBF.LIB with Fortran PowerStation), instead of the one included with MASM 6.11. If you do not use the .LIB file included in the high-level language, you will receive an "Access Violation" error message when you attempt to run a MASM application in either the 32-bit Visual C++ or 32-bit Fortran PowerStation integrated development environment. .FPO Directive -------------- The .FPO directive controls the emission of debug records to the .debug$F segment or section. This directive was originally included with MASM386 and is not supported by MASM 6.11. If you are using both MASM 6.11 and MASM386, the following allows you to continue to implement the .FPO directive:
IF @version LT 600 .FPO ENDIF INVOKE Command -------------- The MASM 6.x INVOKE command does not support transferring control between 16-bit and 32-bit code segments. When the assembler encounters an INVOKE command in a 16-bit segment, it assumes that the procedure being invoked is also in a 16-bit segment; if the assembler encounters an INVOKE in a 32-bit segment, it assumes that the invoked procedure is also in a 32-bit segment.
To avoid this problem, push the necessary parameters on the stack and make the appropriate call instead of using INVOKE.
LINK and System Resources ------------------------ You may encounter the following error message when running LINK on Windows 3.1: System resource exhausted. Abort, Retry, Fail?
This may occur because LINK opens a large number of files, and the buffer for SHARE may have been exceeded. To fix this problem, edit your AUTOEXEC.BAT, setting the following values for SHARE:
/L:500 /F:4096
MOUSE.COM --------- Microsoft Mouse Driver (MOUSE.COM) Version 8.20a is included with MASM 6.11. If you have a later version of the Microsoft Mouse installed on your system, it is recommended you use it instead of the Mouse Driver included with MASM 6.11.
MS-DOS and Windows NT File Compatibility ---------------------------------------- Files installed on the Microsoft Windows NT File System (NTFS) are accessible only on Microsoft Windows NT. Files installed on the MS-DOS File System (FAT) are accessible on MS-DOS, Microsoft Windows, or Microsoft Windows NT.
Multi-File Assembly with MASM.EXE --------------------------------- When assembling multiple files with MASM.EXE, you must terminate the command-line with a semi-colon or a comma (for example, MASM *.asm;). Failure to do this may cause the program to appear to hang if you are running Microsoft NT. If this does occur, you can terminate the program with Ctrl+C.
NMAKE and NMAKER ---------------- MASM 6.11 includes two versions of the NMAKE project management utility. NMAKER.EXE is a real-mode version of the utility. NMAKE.EXE is a driver program which first loads the MS-DOS extender DOSXNT into memory, and then runs NMAKER.EXE. Using the NMAKE.EXE driver will result in faster build times. Some development tools from other manufacturers may be incompatible with NMAKE.EXE. If you encounter incompatibilities, use NMAKER.EXE instead.
Response Files -------------- Information on response files is not included in the MASM 6.1 manuals; however, this information can be found in "ML Command Line Options" in Online help. SAMPLES.TXT and NTSAMPLE.TXT ---------------------------- SAMPLES.TXT contains information about the MASM samples for MS-DOS/Windows; NTSAMPLE.TXT contains information about the samples given for MASM for Windows NT. Both files include information about additional tools you may need to build some of the samples. If you choose to install the sample code during the setup process, both SAMPLES.TXT and NTSAMPLE.TXT are included. SAMPLES.TXT can be found in the \MASM611\SAMPLES subdirectory; NTSAMPLE.TXT can be found in the \MASM611\SAMPLES\NTSAMPLE subdirectory.
Using Control-C to Halt Operation of MASM ----------------------------------------- MS-DOS applications running under DPMI, such as ML.EXE, may not respond immediately to pressing Control-C. If you press Control-C, and ^C appears on the screen but you are not returned to MS-DOS, press the Enter key.
Using MASM 6.x Structures ------------------------- MASM 6.x supports a more powerful syntax for structure definition and usage than previous versions of MASM. This more powerful syntax is enabled by default. To use the older syntax, issue the OPTION OLDSTRUCTS directive (see Appendix A of the MASM Programmer's Guide for more information).
Note: use of nested structures requires the new MASM 6.x syntax. If you use nested structures, the OPTION OLDSTRUCTS directive will be ignored for the structure which is nested.
Visual C++ 1.0/Fortran PowerStation 1.0 Compatibility ----------------------------------------------------- There are specific steps you must take to use MASM 6.11 with Microsoft Visual C++ 1.0 or Microsoft Fortran PowerStation 1.0. If you wish to do mixed language programming with these products, it is recommended that:
- You install Visual C++/Fortran PowerStation and MASM 6.11 in separate sub-directories.
- You place \MSVC\BIN or \F32\BIN (your Visual C++ or Fortran PowerStation sub-directory) first on your path statement before \MASM611\BIN (your MASM 6.11 sub-directory).
- You use NMAKE.EXE from MASM 6.11. You can do this using various methods, such as moving or renaming NMAKE.EXE installed in \MSVC or \F32 thus causing the system to continue searching your path and use the NMAKE.EXE in \MASM611.
Optionally, for MASM 6.11/Visual C++ mixed programming, you may use NMAKER.EXE which is installed with both products.
When using the LINK utility included with Visual C++ 1.0, you may encounter one or both of the following warnings:
LINK : warning L4017: /r : unrecognized option name; option ignored CVPACK : warning CK4007 : unrecognized option /x; option ignored These warnings do not affect the resulting program and should be ignored. Working with MASM 5.1 Code -------------------------- MASM 6.x offers major advances over previous versions of MASM. Some of these improvements require changes that make MASM 5.1 source code incompatible with MASM 6.x. To provide compatibility with code written for MASM 5.1, MASM 6.x allows you to access MASM 5.1 compatibility code in three ways: - By using the conversion driver MASM.EXE. MASM.EXE converts your existing command-line options to the new syntax, adds the compatibility option /Zm, and invokes ML.EXE. - By using ML.EXE with the /Zm option. You also need to convert command-line options to the new syntax. - By placing the statement OPTION M510 at the beginning of each file. You also need to convert command-line options to the new syntax. In most cases, using the /Zm option or OPTION M510 will be the best solution for assembling existing code. If you prefer to modify your code so it can be assembled without /Zm or OPTION M510, do the following: 1. Add the appropriate OPTION directives to your code.
- Always add the following:
OPTION OLDSTRUCTS ; Supports old-style structures OPTION OLDMACROS ; Supports old-style macros OPTION DOTNAME ; Supports naming identifiers with ; a leading dot [.]
- If your code does not specify the .386 or .386P directive, add the following:
OPTION EXPR16 ; Use 16-bit precision in expressions
- If your code does not contain a .MODEL directive, add the following:
OPTION OFFSET:SEGMENT ; Specifies that the OFFSET operator ; defaults to segment-relative rather ; than group-relative
- If your code does not contain a .MODEL directive or if the .MODEL directive does not specify a language, add the following:
OPTION NOSCOPED ; Makes code labels global rather than ; local to the procedure in which they ; appear OPTION PROC:PRIVATE ; Makes code labels defined with PROC ; local unless specified otherwise
2. Once your code assembles with the OPTION directives, remove each OPTION directive, one at a time, and reassemble the code after you remove each one.
Usually, it is best to remove the OPTION directives in the opposite order in which you added them. In some cases, you may decide that you prefer the MASM 5.x compatibility behavior instead of the new MASM 6.x behavior. When this is true, do not remove the corresponding OPTION statement from your code. For more information on assembling MASM 5.1 code, see Appendix A of the MASM Programmer's Guide.
Working With Microsoft BASIC Far Strings --------------------------------------------- The BASIC runtime function StringAssign does not correctly handle strings of zero length. Instead of calling StringAssign to convert a zero-length string, simply return a near pointer to a doubleword with the value 0.

======================<>====================
Exiting from MS-DOS Critical Errors -------------------------------------------------- MS-DOS critical errors, such as attempting to assemble a file on a drive which does not exist or is empty, produce the "Abort, Retry or Fail?" error message. Selecting "Abort" when running MASM in MS-DOS may cause memory to be corrupted. This problem does not occur when running MASM in Windows. To avoid this problem, select "Retry" or "Fail", as appropriate.
Expression Order in High-Level Conditionals -------------------------------------------------- Comparisons in high-level conditionals cannot begin with a literal. For instance, this comparison causes an error:
.IF 1 == AX
but this works properly:
.IF AX == 1
Hexadecimal Constants --------------------- In some instances, ML might not generate the appropriate error message if it encounters a hexadecimal constant that does not have an appending "h". The following will help to ensure that hexadecimal constants are properly represented:
- Make sure that all hexadecimal constants have an appending "h". - Begin all hexadecimal constants with the numeral 0. This ensures that the compiler will generate the appropriate error message if it encounters a hexadecimal constant that does not end in "h".
Initializing Nested Structures -------------------------------------------------- If one structure is nested within another, the inner structure's initializer list must either be empty or include a comma between every field. For example, the structure INFO declared on page 123 of the Programmer's Guide contains a structure of type DISKDRIVES, which in turn contains three BYTE fields. An object of type INFO could be initialized as:
Info1 INFO { , , , , { }} ; Inner initializer list is blank
or as:
Info1 INFO { , , , , {1, 2, }} ; Commas for all three fields
but not as:
Info1 INFO { , , , , {1, 2 }} ; Error: missing last comma
Intersegment Near Jumps in Flat Model ------------------------------------- Intersegment near jumps do not work across files (externs) in flat model. When programming in flat mode, make sure that all intersegment near jumps occur within the same file. Span-Dependent Expressions used in Macros -------------------------------------------------- MASM 6.1x evaluates macro expressions only on the first pass of assembly, but code and data are reevaluated on subsequent passes. Because of this, macro expressions which depend on the span between two addresses may not evaluate correctly. For instance, the following code will not evaluate correctly:
Label1: JMP Label2 Label2:
REPEAT Label2 - Label1 ; Evaluates incorrectly INC AX ENDM
View the listing file to determine if a questionable macro expression was evaluated as desired.
Span-Dependent Equates in Macros and EXTERNDEF ABS --------------------------------------------------- The ABS operator causes an identifier to be exported as a relocatable unsized constant (see Programmer's Guide page 220). If ABS is used with EXTERNDEF within a macro, and the constant being exported depends on the difference between two addresses, the constant may not be exported correctly. In some cases, the listing file will show the correct value, but the value in the resulting .obj will be incorrect. For instance, the following code will not evaluate correctly:
EXTERNDEF TableSize:ABS ; Will not be exported correctly
MAKETABLE MACRO Table1 LABEL BYTE DB 0, 1, 2 TableSize EQU $-Table1 ENDM
SEG1 SEGMENT MAKETABLE SEG1 ENDS
To avoid this problem, either use the 'PUBLIC' directive in place of 'EXTERNDEF', or put a label before the equate, within the macro.
Span-Dependent Text Equates -------------------------------------------------- The TEXTEQU operator is evaluated on the first assembly pass. If TEXTEQU is used with an expression that depends on the difference between two addresses, the resulting constant may be incorrect. For instance, the following code will not evaluate correctly:
Label1: JMP Label2 Label2: WrongNum TEXTEQU %Label2-Label1 ; WrongNum will be incorrect

STRUCT and RECORD Initialization -------------------------------- If a STRUCT containing a UNION is initialized incorrectly, it is possible that the compiler might not generate an appropriate error. If the UNION contains a RECORD, the STRUCT is initialized to the default value for the original UNION. Using The /link /nologo Command Line Options ---------------------------------------------------------

The /link command line option for ML causes all following parameters to be passed to the linker. If the /nologo command line option is passed to the linker, the linker may parse other parameters incorrectly. To avoid this problem, use the /nologo command line switch for ML rather than passing it to the linker. For instance, replace:
ML hello.asm /link /nologo MYLIB.LIB
with:
ML /nologo hello.asm /link MYLIB.LIB
Alternately, you may use the NMAKE utility to automate building your project.

MASM611

2005-10-03T17:47:00.000-07:00

Configuring MASM 6.11 on your home computer
People seem to have a difficult time installing MASM 6.11 on their home computers. Here are a few suggestions that you need to follow. These are from the Getting Started manual that comes with the documentation for MASM 6.11. It is the very thin manual, but the most important. But who reads manuals?????

Installing Device Drivers
If you are running MASM6.11 from Windows 3.1 or Windows 95, then you will need to add the following line to your SYSTEM.INI file. This file should be located in your Windows directory. Alternatively, you can run the program sysedit, this will bring up all your system files (In Win95: Start, Run..., sysedit; in Win3.1: File, Run, sysedit).
You should verify that the files that you are adding in the DEVICE statements are on your system. Use Windows Explorer to look into the BIN and BINR directories and verify that each of these files exists and is in the correct directory. Make any modifications to the statements to agree with where the files are located on your system. If a file does not exist, then do not include that DEVICE statement in SYSTEM.INI.; Add these lines to the [386Enh] section of the SYSTEM.INI file in ; your Windows directory. The changes will not take effect until
; you exit and restart Windows.
;
; If your SYSTEM.INI file already contains DEVICE= statements with
; the same filenames, replace the old DEVICE= statements with the ones
; shown here. Windows 3.x will not run if the SYSTEM.INI file contains
; more than one DEVICE= statements for a single driver.
;
; If your SYSTEM.INI file contains a DEVICE= statement for CV1.386,
; a driver which is no longer necessary, Windows 3.x will not run.
; Remove the DEVICE=CV1.386 statement to solve this problem.
device=C:\MASM611\BIN\dosxnt.386
device=C:\MASM611\BINR\cvw1.386
device=C:\MASM611\BINR\vmb.386

Setting Environment Variables
Regardless of which operating system you are using, you must have certain environment variables set in order for MASM 6.11 to work properly. There are three methods for doing this:
Changing AUTOEXEC.BAT
One method is to permanently change the AUTOEXEC.BAT file. To do this, add the following lines to your AUTOEXEC.BAT file located in the root directory of you C: drive.SET PATH=C:\MASM611\BIN;C:\MASM611\BINR;%PATH%SET LIB=C:\MASM611\LIB;%LIB%SET INCLUDE=C:\MASM611\INCLUDE;%INCLUDE%SET INIT=C:\MASM611\INITSET HELPFILES=C:\MASM611\HELP\*.HLPSET TMP=C:\WINDOWS\TEMP

Running MASM 6.11 from a batch file
The other method is to leave AUTOEXEC.BAT alone, but to always run the Programmer's Workbench from a batch file. Create a text file named run-pwb.bat containing the following lines:SET PATH=C:\MASM611\BIN;%PATH%SET LIB=C:\MASM611\LIB;%LIB%SET INCLUDE=C:\MASM611\INCLUDE;%INCLUDE%SET INIT=C:\MASM611\INITSET HELPFILES=C:\MASM611\HELP\*.HLPSET TMP=C:\WINDOWS\TEMPPWBWhenever you want to run the Programmer's Workbench, then run this batch file.
Running a batch file to set the environment variables
When you install MASM 6.11, a file named NEW-VARS.BAT is created in the BINR directory. It is possible to run this command from a DOS prompt, then you will have access to all the commands you need: MASM, ML, CV, DEBUG.

Start a DOS window.
Type the commandC:\MAMS611\BINR\NEW-VARS.BAT
You will have access to all the commands from this DOS window. If you open a new DOS window, you will have to run NEW-VARAS.BAT again.
Running Out of Environment Space
The information that you add to the AUTOEXEC.BAT file or to the .BAT file that you create to run PWB takes a lot of environment space. The default size of the environment is 256 bytes. This usually is not enough for all the variables that are being set. So, if you ever get an error message that says Out of environment space
Then add the following line to the CONFIG.SYS file: shell=c:\command.com /e:1024 /p
The /e:1024 will give you 1024 bytes of environment space, if that isn't enough then try 2048. The /p indicates that COMMAND.COM should remain loaded and that AUTOEXEC.BAT should be executed.

DOS Installation Only
If you are trying to run MASM 6.11 from DOS, then you should make the following changes to your config.sys file. If you are running from Windows 3.1 or Windows 95 then you won't need to add these lines. If you install MASM 6.11 on a drive other than C: or in a directory other than MASM611, then you will need to make the appropriate changes below. files=20
buffers=10
device=C:\MASM611\BIN\himem.sys
device = C:\MASM611\BIN\emm386.exe 8192 RAM
REM Use the following line to run CodeView without Windows or 386MAX loaded.
REM device = C:\MASM611\BIN\emm386.exe 2048 RAM

http://www.cs.fiu.edu/~downeyt/cop3402/masmconf.html
http://www.cs.fiu.edu/~downeyt/cop3402/runmasm.html
MASM611 Readme File

Chapter 10 (Data Communication)

2005-09-30T02:24:00.001-07:00

TITLE Fig. 10.3

;Function: Serial data transmitter. DELAY
; procedure determines data rate.
;Inputs: Character to be transmitted assumed
; passed in AL.
;Ouputs: Serial data on bit 0 of DPORT.
;Destroys: AL,CX,flags.
;Note: To assemble this program include Chap10.Lib
;under Link Options - Additional Global Libraries

EXTRN DELAY:NEAR
DPORT EQU 00H

CODE SEGMENT 'CODE'
ASSUME CS:CODE

FIG10_3 PROC NEAR
MOV CX,10 ;10 bits/char
CLC ;Start bit
RCL AL,1 ;Move to position 0
TRANS: OUT DPORT,AL ;Transmit bit
CALL DELAY ;Wait
RCR AL,1 ;Next bit
STC ;Stop bit
LOOP TRANS ;Do 10 times
RET
FIG10_3 ENDP
CODE ENDS
END

TITLE FIG 10.33

;Function: Append BCC byte to a data block
;Inputs: Block address passed in DS:SI
;Outputs: BCC added to the block as last byte
;Calls: nothing
;Destroys: flags,CX,SI,AL,BL

;Program Equates

BLOCK_SIZE EQU 255

;Procedure Begins

CODE SEGMENT 'CODE'
ASSUME CS:CODE

BCC PROC NEAR
CLD ;Auto increment
MOV CX,BLOCK_SIZE ;CX is counter
MOV BL,0 ;Sum to BL
SUM: LODSB ;Get one byte
ADD BL,AL ;Accumulate sum
LOOP SUM ;Do until CX=0
NEG BL ;Form 2s compl
MOV [SI],BL ;Append BCC
RET ;Done
BCC ENDP
CODE ENDS
END

Chapter 9(Interrupt and DMA)

2005-09-30T02:24:00.000-07:00

Page 43,132
Title Figure 9.16

.386

;*******
; Parallel Printer Device Driver -
; Interrupt vector table, device control
; block, program equates
;*******

; Set up segment at absolute address 0000
; Printer generates type 0F (IRQ7) interrupt
; See Table 4.5

INT_VEC_TABLE SEGMENT AT 0
ORG 0FH*4
PRINT_INT LABEL DWORD
INT_VEC_TABLE ENDS

;Set up and initialize the device control block

DEV_CTRL_BLK SEGMENT BYTE

;The following equates define the status byte

GOOD EQU 00H ;Good transfer
ERROR EQU 01H ;Previous print in progress
PIP EQU 02H ;Print in progress flag

STATUS DB GOOD ;Current print status
BUF_ADDR DD 20000000H ;Print buffer starting address
CHAR_COUNT DW ? ;Number of bytes to be printed
CHAR_XFER DW ? ;Current number of bytes
;transferred
DEV_CTRL_BLK ENDS

;Printer equates (see Fig. 8.7 for hardware interface)

PR_PORT EQU 378H ;LPT1 port A
PR_STATUS EQU 379H ;LPT1 status
PR_CTRL EQU 37AH ;LPT1 control
INIT EQU 1AH ;Unidirectional, IRQ7 enable,
;sel printer, init, auto
STROBE_LOW EQU 1FH ;STROBE low
STROBE_HIGH EQU 1EH ;STROBE high
BUSY EQU 80H ;Mask for BUSY/READY - bit D7

;8259A PIC equates (see Fig. 9.6 for hardware interface)

ICW1 EQU 00010011B ;Edge triggerred,single,ICW4 to follow
ICW2 EQU 00001000B ;PIC base vector = 08H (IRQ7 = type 0FH)
ICW4 EQU 00000001B ;NSFNM,non buffered,normal EOI,8086
PIC_A EQU 20H ;PIC base port address
PIC_B EQU 21H ;Second port
EOI EQU 20H ;OCW2 - nonspecific EOI

;*******
; Parallel Printer Device Driver -
; Initialization routines
;*******

CODE SEGMENT 'CODE'
ASSUME CS:CODE, DS:INT_VEC_TABLE

;Load printer interrupt vector

START: CLI ;No interrupts until initialized
MOV AX,0 ;Base of INT_VEC_TABLE
MOV DS,AX ;Point DS at INT_VEC_TABLE
MOV PRINT_INT,OFFSET PR_ISR ;Store offset of printer ISR
MOV PRINT_INT+2,SEG PR_ISR ;Store segment of printer ISR

;Ouptut PIC program codes

MOV AL,ICW1 ;Program PIC
OUT PIC_A,AL
MOV AL,ICW2
OUT PIC_B,AL
MOV AL,ICW4
OUT PIC_B,AL

;Initialize printer, set STROBE line high

MOV AL,INIT ;Initialization code
MOV DX,PR_CTRL
OUT DX,AL
MOV AL,STROBE_HIGH
OUT DX,AL

;*******
; Parallel Printer Device Driver -
; Main program
;*******

;Normal processing occurs

;User requests a file to be printed

ASSUME CS:CODE, DS:DEV_CTRL_BLK ;Following labels are in DEV_CTRL_BLK
PUSH DS ;Save main program's DS
MOV AX,DEV_CTRL_BLK ;Point DS at DEV_CTRL_BLK
MOV DS,AX
CALL COM_PROC ;Transfer control to command processor

;Command processor returns control to main
;program after starting the I/O. STATUS
;holds error condition (if any).

CMP STATUS,ERROR ;Was a print already in progress?
POP DS ;Recover main program's DS
JE ERROR_ROUTINE ;Notify user of error

;Normal processing now resumes (simulated by
;the closed loop that follows)

SIMU: NOP
JMP SIMU

ERROR_ROUTINE:
;This routine might notify the user that a
;previous print job is already in progress.
;Control then returns to the main program.

JMP SIMU ;Just a dummy in this case

;*******
; Parallel Printer Device Driver -
; Commmand processor procedure
;*******

;Function: Process print command and specify
; DEV_CTRL_BLK parameters.
;
;Inputs: DS assumed to point at DEV_CTRL_BLK
;Outputs: STATUS=ERROR if previous print in
; progress, else STATUS=PIP.
;Calls: Printer ISR to start I/O.
;Destroys: flags

COM_PROC PROC NEAR
CMP STATUS,GOOD ;Make sure previous print complete
JE SKIP ;Else
MOV STATUS,ERROR ;Let STATUS = ERROR
JMP SHORT QUIT ;And quit
SKIP: MOV CHAR_XFER,0 ;Reset characters transferred to 0
MOV CHAR_COUNT,512 ;This example prints 512 byte buffers
MOV STATUS,PIP ;Update STATUS to print-in-progress
INT 0FH ;Start the first byte "manually" (IRQ7)
STI ;Remaining bytes will print automatically
QUIT: RET ;So return to main program
COM_PROC ENDP

;********
; Parallel Printer Device Driver -
; Printer interrupt service routine
;********

;Function: Output bytes from buffer to
; printer port until printer is
; BUSY.
;Inputs: Data to be printed stored
; beginning at BUF_ADDR
;Outputs: Data to be printed at PR_PORT.
; Returns with STATUS=GOOD when
; all bytes printed.
;Calls: Nothing
;Destroys Nothing

PR_ISR PROC NEAR
PUSH SI ;Save any registers about to be changed
PUSH DS
PUSH AX

POLL: MOV DX,PR_STATUS ;Get printer status
IN AL,DX
TEST AL,BUSY ;If printer BUSY (or off-line)
JNZ EXIT ;Then exit this procedure
MOV AX,DEV_CTRL_BLK ;Make sure DS points to DEV_CTRL_BLK
MOV DS,AX
MOV AX,CHAR_XFER ;Check to see if all bytes
CMP AX,CHAR_COUNT ;have been printed.
JE JOB_DONE ;Then the job is done
PUSH DS ;Save DEV_CTRL_BLK segment
LDS SI,BUF_ADDR ;Point DS at base of the print buffer
ADD SI,AX ;Point SI at character to be printed
MOV AL,[SI] ;Fetch the byte
MOV DX,PR_PORT ;LPT1 port A
OUT DX,AL ;Output byte to printer
MOV AL,STROBE_LOW ;Strobe the printer
MOV DX,PR_CTRL
OUT DX,AL
MOV AL,STROBE_HIGH
OUT DX,AL
POP DS ;Recover DEV_CTRL_BLK segment
INC CHAR_XFER ;Update characters transferred
JMP POLL ;See if printer will accept another

JOB_DONE:
MOV STATUS,GOOD ;When all bytes printed STATUS=GOOD

EXIT: MOV AL,EOI ;Reset interrupt within PIC
OUT PIC_A,AL
POP AX ;Restore used registers
POP DS
POP SI
IRET ;Return to main program

PR_ISR ENDP
CODE ENDS
END START

Chapter 8 (Programmed I/O)

2005-09-30T02:22:00.000-07:00

TITLE Fig. 8.3

;Function: Test if bits 13, 11, 3 or 2 of
; the 16-bit data port are high.
;Inputs: Status information from IPORT.
;Outputs: CF=1 if condition TRUE, else CF=0.
;Destroys: AX, flags.

PUBLIC FIG8_3
IPORT EQU 0H ;Data input port

CODE SEGMENT BYTE PUBLIC 'CODE'
ASSUME CS:CODE

FIG8_3 PROC NEAR
CLC ;Be sure CF=0
IN AX,IPORT ;Sample data
TEST AX,0010100000001100B ;Test input data
JZ DONE ;No bits high
STC ;At least 1 bit high
DONE: RET
FIG8_3 ENDP
CODE ENDS
END

TITLE Fig. 8.5

;This program calls the routine in Fig. 8.3.
;If switches 13, 11, 3 or 2 are open, FFH is
;output to OPORT, else 00 is output.
;Note: To build this program specify Chap8.Lib
;under Link Options - Additional Global Libraries.

EXTRN FIG8_3:NEAR
OPORT EQU 0 ;Output port

CODE SEGMENT 'CODE'
ASSUME CS:CODE

START: MOV BL,0FFH ;Open switches code is FF
CALL FIG8_3 ;Test switches
JC SET ;Condition met
MOV BL,0 ;Condition not met code is 00
SET: MOV AL,BL ;Code to AL
OUT OPORT,AL ;Program the port
JMP START ;Monitor continuously
CODE ENDS
END START

TITLE Fig8.10

;Function: Polled printer driver for LPT1.
; Written as a far procedure. .
;Inputs: PRINT_DATA segment holds number of bytes
; to be printed and the address of the buffer.
;Outputs: Characters in the buffer are output to LPT1.
;Calls: None
;Destroys: AX, CX, SI, DS, flags

PRINT_DATA SEGMENT WORD
NUMB DW ? ;Number of bytes to print
ADR DD ? ;Address of first byte

PRINT_DATA ENDS

LPT1 EQU 378H ;Printer data port
STATUS EQU 379H ;Printer status port
Control EQU 37AH ;Printer control port
INIT EQU 0AH ;Unidirectional, no IRQ,
;select printer, init, auto
;STROBE=1
S_HIGH EQU 0EH ;STROBE=1 and no init
S_LOW EQU 0FH ;STROBE=0 and no init

CODE SEGMENT 'CODE'
FIG8_10 PROC FAR
ASSUME CS:CODE, DS:PRINT_DATA

;Initialize pointers:
; DS:SI to start of data
; CX with number of bytes to be printed

MOV AX,PRINT_DATA ;Load DS with
MOV DS,AX ;address of PRINT_DATA.
MOV CX,NUMB ;Get number of bytes
LDS SI,ADR ;Get address of data
;to DS:SI.
CLD ;Auto increment

;Initialize and select printer, auto line feed, STOBE=1
MOV AL,INIT ;Initialization code
MOV DX,CONTROL ;Control port access
OUT DX,AL ;Write the code

;Poll the printer waiting for BUSY to be low

POLL: MOV AL,S_HIGH ;Be sure STROBE is high
OUT DX,AL ;Write to control port
MOV DX,STATUS ;Status port access
IN AL,DX ;Get BUSY status
TEST AL,10000000B ;Test BUSY bit
JZ POLL ;Wait until READY

;Printer is ready, fetch and output a byte
LODSB ;Get byte
;and advance pointer.
MOV DX,LPT1 ;Data port access
OUT DX,AL ;Output to printer

;Strobe the printer
MOV AL,S_LOW ;STROBE=0
MOV DX,CONTROL ;Control port access
OUT DX,AL ;Write to LPT1 control port

;Repeat the polling loop until all data has been printed
LOOP POLL ;Do CX times

RET ;Then return
FIG8_10 ENDP
CODE ENDS
END

TITLE FIG. 8.16

;Function: Scan the keyboard shown in Fig. 8.14
; and return with the encoded key
; value in register AL.
;Inputs: none
;Outputs: hex key value in AL.
;Calls: 10 ms delay procedure for debouncing
;Destroys: AX and flags

;*******
; Set up segment to store key values
;*******

KEY_CODE SEGMENT BYTE
COL1 DB 0,1,2,3,4
DB 5,6,7
COL2 DB 8,9,0AH,0BH,0CH
DB 0DH,0EH,0FH
KEY_CODE ENDS

CODE SEGMENT BYTE 'Code'
ASSUME CS:CODE,DS:KEY_CODE

;*******
;Program equates
;*******

PORT_A EQU 00H ;PPI port A address (see Fig. 8.12)
PORT_C EQU 08H ;PPI port C address
COL_1_LOW EQU 10111111B ;PC6 low
COL_2_LOW EQU 01111111B ;PC7 low
BOTH_COL_LOW EQU 00111111B ;PC6 and PC7 low
KEY_UP EQU 0FFH ;Input 0FFH when no keys are down
T1 EQU 8B82H ;~ 10 ms time delay assuming 25MHz 80486

;*******
; 10 ms time delay for debouncing
;*******

DELAY PROC NEAR
MOV CX,T1
COUNT: LOOP COUNT
RET
DELAY ENDP

;*******
; Main program begins here
;*******

KEYBOARD PROC NEAR
PUSH DS ;Save registers about to be used
PUSH CX
PUSH SI
MOV AX,KEY_CODE ;Point DS to the key codes
MOV DS,AX

;Wait for previous key to be released

MOV AL,BOTH_COL_LOW ;Scan both columns
OUT PORT_C,AL ;Column lines on PC6 and PC7
POLL1: IN AL,PORT_A ;Read keyboard
CMP AL,KEY_UP ;All keys up?
JNE POLL1 ;No - so wait
CALL DELAY ;Yes - wait for bounce on release

;Wait for a new key to be pressed

POLL2: IN AL,PORT_A ;Read keyboard
CMP AL,KEY_UP ;Any keys down?
JE POLL2 ;No - so wait
CALL DELAY ;Yes - wait for bounce

;See if the key is in column 1

MOV AL,COL_1_LOW ;Test for column 1
OUT PORT_C,AL ;PC6 low
IN AL,PORT_A ;Read column 1 keys
CMP AL,KEY_UP ;Any key down?
JE CHECK_COL_2 ;No - check for column 2
LEA SI,COL1 ;Yes - point SI at the key values 0-7
JMP LOOKUP ;Now lookup code

;If not column 1 then column 2

CHECK_COL_2: MOV AL,COL_2_LOW ;Test for column 2
OUT PORT_C,AL ;PC7 low
IN AL,PORT_A ;Read column 2 keys
CMP AL,KEY_UP ;Any key down?
JE POLL2 ;No - false input so repeat
LEA SI,COL2 ;Yes - point SI at key values 8-F

;Now lookup the key's value and store in AL

LOOKUP: RCR AL,1 ;Rotate keyboard input code right
JNC MATCH ;If 0 key is found - so retrieve it
INC SI ;No - advance pointer to next value
JMP LOOKUP ;Repeat the loop

MATCH: MOV AL,[SI] ;Get the key code
POP SI ;Restore all registers
POP CX ;(except AX and flags)
POP DS
RET
KEYBOARD ENDP
CODE ENDS
END

Chapter 6 (.com & .exe)

2005-09-30T02:18:00.000-07:00

The Assemblers (MASM, MASM611 & TASM3.0)

Use PWB to generate .com file
Step 1: Open .ASM file
Step 2: Building the program
Before building program, several options in PWB should be set.
a. Project template: select .com.
b. Build options : Select Debug options
c. Language option : Select MASM
Step 3 : Select Project Build menu option.
********************************************************

Page 58,132
Title Program 5.1

;*******************************************
; Display ASCII Character Set *
;* *
;* This program displays all of the ASCII *
;* characters with codes 0-127. *
;* *
;*******************************************

cseg segment 'code'
assume cs:cseg, ds:cseg, ss:cseg, es:cseg

org 100h ;Leave room for PSP

start: mov ax,0002 ;BIOS service 0, video mode 2
int 10h ;Set video mode and clear screen
mov ah,2 ;BIOS service 2
mov dx,0a00h ;Row 10, column 0
mov bh,0 ;Page 0
int 10h ;Position cursor
mov ax,0e00h ;BIOS service 0E, first character is 0
IIA: int 10h ;Print character
inc al ;Next
cmp al,80h ;Done?
jnz IIA ;No: loop again
int 20h ;Yes: back to DOS

cseg ends
end start

Page 43,132
Title Program 5.3

.8086

;****************************************************
;* 8-Bit BCD Adder *
;* *
;* This program inputs two packed BCD numbers from *
;* the keyboard, computes their sum and outputs the *
;* result to the screen. *
;* *
;* Example: The user types: 62+34= *
;* The computer responds: 96 *
;****************************************************

;************************
;* Stack Segment *
;************************
sseg segment stack
db 32 dup (?) ;32 bytes for stack
sseg ends

;************************
;* Data Segment *
;************************
dseg segment
buff db 8 dup (?) ;8 byte input buffer
dseg ends

;************************
; Code Segment *
;************************
cseg segment 'code'
assume cs:cseg, ds:dseg, ss:sseg

main: mov ax,dseg ;Get address of data segment
mov ds,ax ;and store in DS

lea dx,buff ;Point DX at input buffer
mov ah,0ah ;DOS function 0AH
mov si,dx ;Point Si at input buffer
mov byte ptr [si],8 ;8 byte buffer
int 21h ;Get the two numbers
mov ah,0eh ;BIOS video service
mov al,0ah ;ASCII line feed
int 10h
sub byte ptr [si+2],30h ;Convert each digit to BCD
sub byte ptr [si+3],30h
sub byte ptr [si+5],30h
sub byte ptr [si+6],30h
mov cl,4 ;Four rotates
rol byte ptr [si+3],cl ;Form LSD
rol byte ptr [si+6],cl
ror word ptr [si+2],cl ;Add to MSD
ror word ptr [si+5],cl
mov al,[si+3] ;Fetch first BCD number
add al,[si+6] ;Add to second
daa ;Keep results decimal
mov bh,al ;Save results
jnc IIIB ;Check for hundredths digit
mov al,1 ;Set hundredths digit
call dspy ;Display it
IIIB: mov al,bh ;Recover low order result
call dspy ;Display low order result
mov ah,4ch ;Terminate
int 21h ;Return to DOS

;************************
;* Display Procedure *
;************************
; Function: Display Two Digit BCD Number
; Inputs: BCD number in AL
; Outputs: None
; Calls: BIOS interrupt 10H
; Destroys: AL, BL, CL, flags

dspy proc ;Display procedure
mov bl,al ;Save original number
and al,0f0h ;Force bits 0-3 low
mov cl,4 ;Four rotates
ror al,cl ;Rotate MSD into LSD
add al,30h ;Convert to ASCII
mov ah,0eh ;BIOS video service 0E
int 10h ;Display character
mov al,bl ;Recover original number
and al,0fh ;Force bits 4-7 low
add al,30h ;Convert to ASCII
int 10h ;Display character
ret ;Return to calling program
dspy endp

cseg ends
end main

Page 43,132
Title NIM

.286

;******************************************************
;* The Game of NIM *
;* *
;* The game of NIM is played with 15 "sticks." When *
;* it is your turn, you may pick 1, 2, or 3 sticks. *
;* The player to pick up the last stick wins. *
;* *
;* *
;******************************************************

;The following equate statements assign constants to the labels shown.
;This makes the program more readable and will allow global changes to
;the program to be mde more easily.

display_message equ 09h ;DOS INT 21h function 9 (string output)
video_mode equ 0002h ;BIOS INT 10h service 0, video mode 2 (80x25)
cr equ 0dh ;carriage return
lf equ 0ah ;line feed
get_key equ 0 ;BIOS INT 16h service 0 (read next keyboard character)
quit equ 'q' ;Exit by typing q
delay equ 50 ;50 x 65,536 = 3.3s
BIOS_Wait equ 86h ;Bios INT 15h service 86h (wait for time delay)
terminate equ 4ch ;DOS INT 21h function 4ch (terminate with error code)
write_character equ 0eh ;Bios INT 10h service 0eh (write character in TTY mode)

;************************
;* Stack Segment *
;************************
sseg segment stack
db 100 dup (?) ;100 bytes for stack
sseg ends

;************************
;* Data Segment *
;************************
dseg segment

sticks db ? ;This location stores the number of sticks in the pile

nim db 'NIM - A Game of Skill'
db cr,lf,lf,'$'

instruc db 'I have 15 sticks. You may pick'
db ' 1, 2, or 3 sticks. Then I will'
db ' pick.'
db cr,lf
db 'You win if you pick up the last'
db ' 1, 2 or 3 sticks. Type q to quit at any time.'
db cr,lf,lf,'$'

uchce db 'Your choice: $'

lost db cr,lf
db 'YOU WIN!$'

won db cr,lf
db 'I WIN!$'

update db cr,lf,lf
db 'There are now $'

up_end db ' sticks remaining.'
db cr,lf,'$'

mychce db 'My choice is: $'

;This is the table of choices for the computer
choices db 0,1,2,3,1
db 1,2,3,1,1
db 1,1,1,1,2

dseg ends

;************************
; Code Segment *
;************************
cseg segment 'code'
assume cs:cseg, ss:sseg

start: mov ax,dseg ;Load DS
mov ds,ax

;Clear the screen by setting the video mode
mov ax,video_mode ;BIOS service: set video mode
int 10h

;Show NIM sign-on message
lea dx,nim ;Point DX at sign-on message
call show ;Show the message

;Set number of sticks to 15
mov ds:[sticks],15

;Display the program instructions
lea dx,instruc ;Point DX at instructions
call show ;Show the message

;Display the number of sticks remaining in the pile
Turn: call process

;Get the user's choice
lea dx,uchce ;Point to message
call show ;Show the message

mov ah,get_key ;DOS function: wait for next keypress
int 16h ;Character to AL

cmp al,quit ;Quit?
jz dos ;Return to DOS

call cout ;Else display character

;Update the stick counter
sub al,30h ;Remove ASCII bias
sub ds:[sticks],al ;Adjust counter
jz uwin ;If 0, user wins
call process ;Show the new count

;Look up the computer's choice
lea dx,mychce ;Point to message
call show ;Show the message
call think_time ;Time to "think"
lea bx,choices ;Point to base of choice table
mov al,ds:[sticks] ;Get current number of sticks
xlat ;Use this as index into table
mov bl,al ;Save in BL
add al,30h ;Add ASCII bias
call cout ;Display choice

;Update the stick counter and check to see if computer wins
call think_time ;More think time
sub ds:[sticks],bl ;Adjust counter
jz iwin ;If 0, computer wins
jmp turn ;Else next turn

;Come here to process the winner and start over
uwin: lea dx,lost ;Point to message
call show ;Show the message
jmp skip

iwin: lea dx,won
call show

skip: mov ah,get_key ;Any key restarts game
int 16h
jmp start

;Come here to return to DOS
dos: mov ah,terminate ;DOS function: terminate
int 21h

;***************************************
;* Procedure Think_Time *
;* *
;* Function: Create time delay *
;* Inputs: nothing *
;* Calls: BIOS INT 15H service 86H *
;* Modifys: flags *
;***************************************

think_time proc

;Adjust delay equate for desired time interval
pusha ;Save all registers
mov dx,0 ;Time delay in CX:DX (microseconds)
mov cx,delay
mov ah,bios_wait
int 15h ;Do time delay
popa ;Restore registers
ret

think_time endp

;**************************************
;* Procedure Process *
;* *
;* Function: Display number of sticks *
;* remaining in the pile. *
;* Inputs: Counter in [sticks] *
;* Calls: SHOW and COUT *
;* Modifys: flags *
;**************************************

process proc

pusha ;Save all registers

;Print the update message
lea dx,update ;Point DX at message
call show ;Show message

;Display the number of sticks remaining
mov bl,ds:[sticks] ;Copy stick counter to BL
cmp bl,0ah ;Fewer than 10 sticks?
jb units ;Yes:
mov al,31h ;No: So first digit is ASCII '1'
call cout ;Display 1
sub bl,10 ;Get units digit
units: add bl,30h ;Add ASCII bias
mov al,bl ;COUT wants character in AL
call cout ;Display units

lea dx,up_end ;Point DX to end of update message
call show ;Show message

popa ;Restore registers
ret

process endp

;************************************
;* Procedure Show *
;* *
;* Function: Display ASCII message *
;* terminated with $ *
;* Inputs: DX points to message *
;* Calls: DOS INT 21 service 09H *
;* Modifys: flags *
; *
;************************************

show proc

pusha ;Save all registers
mov ah,display_message ;DOS function: string output
int 21h
popa ;Restore registers
ret

show endp

;**************************************
;* Procedure COUT *
;* *
;* Function: Write one character at *
;* current cursor position. *
;* Inputs: character in AL *
;* Calls: BIOS INT 10H service 0EH *
;* Modifys: flags *
;**************************************

cout proc

pusha ;Save all registers
mov ah,write_character ;BIOS service: write character in TTY mode
int 10h
popa ;Restore registers
ret

cout endp

cseg ends
end start

Chapter 5 (Programming Technique)

2005-09-30T02:11:00.000-07:00

;Program 5.1
mov ax,0002 ;BIOS service 0, video mode 2
int 10 ;Set video mode and clear screen
mov ah,2 ;BIOS service 2
mov dx,0a00 ;Row 10, column 0
mov bh,0 ;Page 0
int 10 ;Position cursor
mov ax,0e00 ;BIOS service 0E, first character 0
int 10 ;Print character
inc al ;Next
cmp al,80 ;Done?
jnz 0111 ;No: loop again
int 20 ;Yes: back to DOS

;Program 5.2
mov bl,al ;Save original number
and al,f0 ;Force bits 0-3 low
mov cl,4 ;Four rotates
ror al,cl ;Rotate MSD into LSD position
add al,30 ;Convert to ASCII
mov ah,0e ;BIOS video service 0E
int 10 ;Display character
mov al,bl ;Recover original number
and al,0f ;Force bits 4-7 low
add al,30 ;Convert to ASCII
int 10 ;Display character
int 20 ;Return to DOS

;Program 5.3
mov dx,0160 ;Point DX at input buffer
mov ah,0a ;DOS function 0AH
mov si,dx ;Point Si at input buffer
mov byte ptr [si],8 ;8 byte buffer
int 21 ;Get the two numbers
mov ah,0e ;BIOS video service
mov al,0a ;ASCII line feed
int 10 ;
sub byte ptr [si+2],30 ;Convert each digit to BCD
sub byte ptr [si+3],30
sub byte ptr [si+5],30
sub byte ptr [si+6],30
mov cl,4 ;Four rotates
rol byte ptr [si+3],cl ;Form LSD
rol byte ptr [si+6],cl
ror word ptr [si+2],cl ;Add to MSD
ror word ptr [si+5],cl
mov al,[si+3] ;Fetch first BCD number
add al,[si+6] ;Add to second
daa ;Keep results decimal
mov bh,al ;Save results
jnc 0142 ;Check for hundredths digit
mov al,1 ;Set hundredths digit
call 0147 ;Display it
mov al,bh ;Recover low order result
call 0147 ;Display low order result
int 20 ;Return to DOS
;
;
;*****************************************************
; This is Program 5.2 modified to end with an RET instruction
;*****************************************************
mov bl,al ;Save original number
and al,f0 ;Force bits 0-3 low
mov cl,4 ;Four rotates
ror al,cl ;Rotate MSD into LSD
add al,30 ;Convert to ASCII
mov ah,0e ;BIOS video service 0E
int 10 ;Display character
mov al,bl ;Recover original number
and al,0f ;Force bits 4-7 low
add al,30 ;Convert to ASCII
int 10 ;Display character
ret ;Return to calling program
;
;Input buffer begins here

;Program 5.4.TXT
mov si,012c ;Point SI at music table
cld ;Direction flag to auto-increment
mov ah,0 ;BIOS service 0
int 16 ;Wait for keypress
lodsw ;Fetch note code
mov bx,ax ;Save note code
cmp ax,0000 ;Check for last
jz 0124 ;If it is, then quit
mov al,b6 ;Timer-enable code
out 43,al ;Output to timer
mov al,bl ;Retrieve low order note code
out 42,al ;Ouptut to timer
mov al,bh ;Retrieve high order note code
out 42,al ;Output to timer
in al,61 ;Access speaker control port
or al,3 ;Set speaker control bits
out 61,al ;Enable speaker
jmp 0104 ;Go and wait for another keypress
in al,61 ;Access speaker control port
and al,fc ;Reset speaker control bits
out 61,al ;Turn off speaker
int 20 ;Return to DOS
;
dw 11d1 ;Note code for middle C
dw 0fdf ;D
dw 0e24 ;E
dw 0d59 ;F
dw 0be4 ;G
dw 0a98 ;A
dw 0970 ;B
dw 08e9 ;High C
dw 0000 ;End of data

;Program 5.5 (Get_ALT)
mov ah,12 ;BIOS Service 12
int 16 ;Get extended shift key status
and ah,0a ;Test ALT keys only
mov al,ah ;Return code
mov ah,4c ;DOS Function 4C
int 21 ;Return to DOS with error code

;Program 5.6 (CHECK.COM)
mov al,[82] ;Get drive letter
and al,0f ;Convert to number
dec al ;Adjust for BIOS drive offset
mov dl,al ;Drive number to DL
mov cx,000a ;Prepare for 10 loops
mov ax,0201 ;BIOS service 2, read one sector
mov dh,0 ;Head 0
mov bx,0300 ;Buffer address
push cx ;Save loop counter
mov cx,0001 ;Cylinder 0, sector 1
int 13 ;Read one sector
pop cx ;Recover loop counter
jnc 123 ;If successful, continue
loop 114 ;Else try to read it again
mov al,0 ;Set error code to 0 (10 failures)
jmp 12f ;Go and display the error
push ds ;Save DS (changed by function 1C)
inc dl ;Adjust drive number for DOS
mov ah,1c ;DOS function 1CH
int 21 ;Get media byte
add [bx],al ;Add sectors/cluster
mov al,[bx] ;Code to AL for data look-up
pop ds ;Recover DS
mov bx,0200 ;BX points to base of message table
xlat ;Look up message
mov dl,al ;Offset of message in DX
mov dh,01 ;All messsage are on page 01
mov ah,9 ;DOS function 9
int 21 ;Display message
int 20 ;return to DOS
db 'Invalid drive specification or bad disk$'
db 'Drive not ready$'
db '360KB 5.25"$'
db '1.2MB 5.25"$'
db '720KB 3.5"$'
db '1.44MB 3.5"$'

;Prog5_7 (WAIT.COM)
MOV AL,[0084] ;Get third key stroke
CMP AL,0Dh ;Is it return?
JNZ Short 0135 ;If not then quit
MOV EAX,00000000h ;Prepare EAX to hold time delay
SUB Word Ptr [0082],3030h ;Strip ASCII bias from input
MOV AL,[0082] ;Get tens digit
MOV BL,0Ah ;Multiplier = 10
MUL BL ;Convert to units
ADD AL,[0083] ;Add units digit
MOV EBX,000F4240h ;Multiplier = 1 million
MUL EBX ;Convert units to microseconds
MOV DX,AX ;Store low word result in DX
ROR EAX,10h ;Rotate high word result to low word
MOV CX,AX ;Store low word result in CX
MOV AH,86h ;BIOS INT 15, service 86
INT 15h ;Wait for time delay
INT 20h ;Return to DOS

Chapter4 (Debug)

2005-09-30T02:03:00.000-07:00

;Figure 4.20.TXT
mov ah,0
mov al,[200]
div byte ptr [201]
mov [202],axint 20

;Multiply.TXT
MOV AL,[0200] ;Get first number
MUL BYTE PTR [0201] ;Multiply times the second
MOV [0202],AX ;Store result
INT 20 ;Return control to DOS

;Typer.Txt
mov ah,0 ;Keyboard BIOS service 0
int 16 ;Wait for keypress
cmp al,0 ;Check for a function key
jz 10e ;If found, then quit
mov ah,0e ;Video BIOS service 0E
int 10 ;Write character to screen
jmp 100 ;Do another loop
int 20 ;Return to MS-DOS

;Typer2.TXT
MOV DX,0117 ;Point DX at message
MOV AH,09 ;MS-DOS function 9
INT 21 ;Output message to screen
MOV AH,00 ;Keyboard BIOS service 0
INT 16 ;Wait for keypress
CMP AL,00 ;Check for a function key
JZ 0115 ;If found,then quit
MOV AH,0E ;Video BIOS service 0E
INT 10 ;Write character to screen
JMP 0107 ;Do another loop
INT 20 ;Return to MS-DOS
db 'Type any letter, number or punctuation key.
'db 'Any F1 to F10 to end program.
'db 0d,0a,0a,'$'

Intel Microprocessor Hardware, Assembly Language

2005-09-19T18:37:00.000-07:00

TIA/EIA 569 Addendum: Backbone and Horizontal Copper Cabling Structure
Cable FAQ
CD-Recordable FAQ HwB: The Hardware Book
Intel 8086 CPU Family Architecture
Intel 80386 Programmer's Reference 1986 Intel 80386 Programmers Reference Manual (1986) Intel 80x86 Instruction Set
An Introduction to Auto-Negotiation
SCSI FAQ
The Enhanced IDE/Fast-ATA FAQ

Assembly Language

2005-09-12T18:24:00.000-07:00

PC Assembly Language (NSAM)
MASM: The Microsoft Macro Assembler
Assembler and 8086 Microprocessor Emulator
Intel 8086 family Opcode/Instruction Documentation.

How computer memory Work?

2005-09-05T18:38:00.000-07:00

Introduction to How Computer Memory Works
Memory Basics
The PC Process
The Need for Speed
Memory Tiers
System RAM
Burst Mode and Pipelining
Cache and Registers
Types of Memory
Lots More Information
Compare Prices for Computer Memory

Serial Port

2005-09-05T18:23:00.000-07:00

Introduction to How Serial Ports Work
UART Needed
The Serial Connection
Going With The Flow
Lots More Information
Compare Prices for Serial Ports

RAM

2005-09-05T18:07:00.000-07:00

Introduction to How RAM Works
RAM Basics
Memory Modules
Error Checking
Common RAM Types
How Much Do You Need?
How to Install RAM
Lots More Information
Compare Prices for RAM

How Modem works?

2005-08-29T18:00:00.000-07:00

Introduction to How Modems Work
The Origin of Modems
300-bps Modems
Faster Modems
Point-to-Point Protocol
Lots More Information
Compare Prices for Modems

LAN,WAN,Erhernet,Router,Repeater

2005-08-29T03:52:00.000-07:00

Introduction to How Ethernet Works
Why Network?
Local Area vs. Wide Area
The Ethernet
Ethernet Basics
Ethernet Terminology
Ethernet Medium
CSMA/CD
Collision Detection
Limitations of Ethernet
Repeaters
Segmentation
Bridges
Routers: Logical Segmentation
Switched Ethernet
Full-duplex Ethernet
Ethernet or 802.3?
Alternative Network Technologies: Asynchronous transfer mode
Lots More Information
Compare Prices for Ethernet

Music.ASM to EXE

2005-08-24T23:37:00.000-07:00

TITLE MUSIC.ASM to convert to EXE
;-----------------------------------------------------------
STSEG SEGMENT para STACK 'Stack'
DB 64 dup(?)
STSEG ENDS
;-----------------------------------------------------------
DTSEG SEGMENT ; C B
NOTES DW 0000H,11D1H,0FDFH,0E24H,0D59H,0BE4H,0A98H,0970H,08E9H
DTSEG ENDS ; the above represent the frequencies for the various notes C - C#
;----------------------------------------------------------
CDSEG SEGMENT ; COMMENTS
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX ; Point to the Data Segment
KeyP: MOV AH,00H ; Set AH for read
INT 16H ; and read the keystroke
SUB AL,30H ; Convert this to a single digit
CMP AL,00H ; Is the value zero then switch off and end
JZ Exit ; Exit the program
MOV SI, OFFSET NOTES ; Obtain the starting address of the notes
shl al,01 ; and calculate shl al,
MOV AH,00H ; Reset the AH for the effective address below
ADD SI,AX ; Point to the correct data
lodsw ; and obtain this value
MOV BX,AX ; and copy this value to BX register
MOV AL,0B6H ; Timer enable code
OUT 43H, AL ; Output to timer
MOV AL,BL ; Retrieve the lower order note code
OUT 42H,AL ; Output this to timer
MOV AL,BH ; Retrieve the higher order note code
OUT 42H,AL ; Output this to timer
IN AL,61H ; Access speaker control port
OR AL,03H ; Set speaker control bits
OUT 61H,AL ; Enable speaker
JMP KeyP ; Wait for another key to be pressed
Exit: IN AL,61H ; Access speaker control ports
AND AL,0fCH ; Reset speaker control bits
OUT 61H,AL ; Turn off speaker
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

Serial Communication

2005-08-24T23:36:00.000-07:00

TITLE SERIAL DATA COMMUNICATION BETWEEN TWO PCS
.MODEL SMALL
.STACK 64
.DATA
MESSAGE DB 'Serial communication via COM2,4800,No P,1 Stop,8-BIT

DATA.',0AH,0DH
DB 'ANY KEY PRESS IN SENT TO OTHER PC.',0AH,0DH
DB 'PRESS ESC TO EXIT','$'

CODE
MAIN PROC
MOV AX,@DATA
MOV DS,AX
MOV AH,09
MOV DX,OFFSET MESSAGE
INT 21H ;initializing COM2
MOV AH,0 ;initialize COM port
MOV DX,1 ;COM 2
MOV AL,0C3H ;4800,NO P,1 STOP,8-BIT DATA
INT 14H ;checking key press and sending key to COM2 to be transfered

AGAIN: MOV AH,01 ;check for key press using INT 16H,AH=01
INT 16H ;if ZF=1,there is no key press
JZ NEXT ;if no key go check COM port
MOV AH,0 ;yes,there is a key press,get it
INT 16H ;notice we must use INT 16H twice,2nd time
;with AH=0 to get the char itself.AL=ASCII char pressed
CMP AL,1BH ;is it esc key?
JE EXIT ;yes EXIT
MOV AH,1 ;no.send the char to COM 2 port
MOV DX,01
INT 14H ;check COM2 port to see there is char, if so get it and display it

NEXT: MOV AH,03 ;get COM2 status
MOV DX,01
INT 14H
AND AH,01 ;AH has COM port status, mask all bits except D0
CMP AH,01 ;check D0 to see if there is a char
JNE AGAIN ;no data, go to monitor keyboard
MOV AH,02 ;yes,COM2 has data:get it
MOV DX,01
INT 14H ;get it
MOV DL,AL ;and display it using INT 21H
MOV AH,02 ;DL has char to be displayed
INT 21H
JMP AGAIN ;keep monitoring keyboard
EXIT: MOV AH,4CH ;exit to DOS
INT 21H

MAIN ENDP
END main

Srting Operation

2005-08-24T23:35:00.001-07:00

Sample program for string operations. Additional programs provided in class.

STSEG SEGMENT
DB 64 DUP(?)
STSEG ENDS

DTSEG SEGMENT
DAT_DICT DB 'Europe'
DAT_TYPED DB 'Euorope'
MESSAGE1 DB 'The spelling is correct','$'
MESSAGE2 DB 'Wrong spelling','$'
DTSEG ENDS

CDSEG SEGMENT
MAIN PROC FAR
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX
MOV ES,AX
CLD
MOV SI,OFFSET DAT_DICT
MOV DI,OFFSET DAT_TYPED
MOV CX,06
REPE CMPSB
JE OVER
MOV DX,OFFSET MESSAGE2
JMP DISPLAY
OVER: MOV DX,OFFSET MESSAGE1
DISPLAY: MOV AH,09
INT 21H
MOV AH,4CH
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN

Sorting Numbers

2005-08-24T23:35:00.000-07:00

Sample program for sorting numbers. Code, test and prepare a flowchart.

STSEG SEGMENT
DB 64 DUP(?)
STSEG ENDS
;-------------------------------------------
DTSEG SEGMENT
DATA1 DB 12H,53H,77H,24H,95H,3H,10H,83H,55H,32H
RESULT DB ?
DTSEG ENDS
;-------------------------------------------
CDSEG SEGMENT
MAIN PROC FAR
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AL,00H
MOV CL,0AH
MOV SI,OFFSET DATA1
YY: MOV BL,[SI]
CMP AL,BL
JLE XX
MOV AL,BL
XX: INC SI
DEC CL
JNZ YY
MOV RESULT,AL
MOV AH,4CH
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN

Sample File

2005-08-24T23:31:00.000-07:00

;Title MYFILE1.ASM
; My first program
STSEG SEGMENT para stack 'stack'
DB 64 dup(?)
STSEG ENDS
;--------------------
DTSEG SEGMENT
DATA1 DB 52H
DATA2 DB 29H
SUM DB ?
DTSEG ENDS
;--------------------
CDSEG SEGMENT
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX
MOV AL,DATA1
MOV BL,DATA2
ADD AL,BL
MOV SUM,AL
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

MYFILE2.ASM
TITLE MYFILE3.ASM to covert to EXE
; Similar to MYFILE2 except that there is a LOOP instruction
;-----------------------------------------------------------
STSEG SEGMENT
DB 64 dup(?)
STSEG ENDS
;-----------------------------------------------------------
DTSEG SEGMENT
COUNT EQU 03
DATA DB 52H,29H,3CH
SUM DB ?
DTSEG ENDS
;----------------------------------------------------------
CDSEG SEGMENT ; COMMENTS
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX ; Point to the Data Segment
MOV CX,COUNT
MOV SI,OFFSET DATA ; Source Index points to Data area
MOV AL,00 ; Reset the accumulator
BACK: ADD AL,[SI] ; Add Data to AL
INC SI ; Increment the pointer
LOOP BACK ; Loop back if counter is not zero (a double instr)
MOV SUM,AL ; Store the final result
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

MYFILE3.ASM
TITLE MYFILE4.ASM to covert to EXE
; Subtraction of negative numbers
;-----------------------------------------------------------
STSEG SEGMENT
DB 64 dup(?)
STSEG ENDS
;-----------------------------------------------------------
DTSEG SEGMENT
DATA1 DB 4CH
DATA2 DB 6EH
DATA3 DB ?
DTSEG ENDS
;----------------------------------------------------------
CDSEG SEGMENT ; COMMENTS
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX ; Point to the Data Segment
MOV DH,DATA1 ; Load the first data
SUB DH,DATA2 ; Subtract with second data
JNC NEXT ; If Carry = 0 then goto NEXT
NOT DH ; If C = 1 perform 1's complement
INC DH ; and increment to get 2's complement
NEXT: MOV DATA3,DH ; and save result in DATA3
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

MYFILE4.ASM
TITLE MYFILE5.ASM to covert to EXE
; Program to perform simple multiplication byte x word
;-----------------------------------------------------------
STSEG SEGMENT
DB 64 dup(?)
STSEG ENDS
;-----------------------------------------------------------
DTSEG SEGMENT
DATA1 DB 6BH
DATA2 DW 12C3H
RESULT3 DW 2 DUP(?)
DTSEG ENDS
;----------------------------------------------------------
CDSEG SEGMENT ; COMMENTS
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX ; Point to the Data Segment
MOV AL,DATA1 ; Load the first data
SUB AH,AH ; AH register must be cleared
MUL DATA2 ; Multiply with second value
MOV BX, OFFSET RESULT3 ; Point to storage of result
MOV [BX], AX ; AX holds the lower value result
MOV [BX]+2,DX ; DX holds the higher value result
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

MYFILE5.ASM
TITLE MYFILE6.ASM to covert to EXE
; Program to perform division doubleword x word

;-----------------------------------------------------------
STSEG SEGMENT
DB 64 DUP(?)
STSEG ENDS
;-----------------------------------------------------------
DTSEG SEGMENT
DATA1 Dd 105432
DATA2 DW 10000
QUOT DW ?
REMAIN DW ?
DTSEG ENDS
;----------------------------------------------------------
CDSEG SEGMENT ; COMMENTS
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,WORD PTR DATA1 ; AX holds lower word
MOV DX,WORD PTR DATA1+2 ; DX has the higher word ( numerator)
DIV DATA2 ; Perform the division
MOV QUOT, AX ; AX holds the quotient
MOV REMAIN,DX ; DX holds the remainder
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

Assemble, link and debug

2005-08-24T23:26:00.000-07:00

Free Download of Assembler (MASM,TASM,NASM and etc..)
Test the following program in the trace mode and record the value of AX, BX and CX for each stage.

MOV AX, 0055
MOV BX, 1043
DIV BH
AND BH, BL
MOV CX, 0402
ROR BL, CL
CLC
SUB AL, BL
MOV CL, CH
SHL BL, CL
CLC
INT 3

Test the following DOS interrupt programs
MOV AH, 02 ; Setup for output character with
MOV DL, 64 ; the character ‘d’
INT 21H
INT 3

MOV AH, 01 ; Setup for echo character with the value stored in AL
INT 21 H
INT 3

The following is an Assembly Language Program ( Go to the C:\ TASM\BIN Directory and type the following using any text editor such as Edit or Notepad).
; My first program
STSEG SEGMENT
DB 64 dup(?)
STSEG ENDS
;--------------------
DTSEG SEGMENT
DATA1 DB 52H
DATA2 DB 29H
SUM DB ?
DTSEG ENDS
;--------------------
CDSEG SEGMENT
MAIN PROC FAR ; Entry point
ASSUME CS:CDSEG,DS:DTSEG,SS:STSEG
MOV AX,DTSEG
MOV DS,AX
MOV AL,DATA1
MOV BL,DATA2
ADD AL,BL
MOV SUM,AL
MOV AH,4CH ; Exit to DOS
INT 21H
MAIN ENDP
CDSEG ENDS
END MAIN ; Exit from program

Counter, Loop and Stack

2005-08-24T23:23:00.000-07:00

Complete all of the above and submit this TUTORIAL / ASSIGNMENT.
In this session we shall discuss about counters and the various modes of operation depicted in the following examples. You should to try and fill up the uncommented areas in Problems 2&3.

1. Down counter
MOV CL, 03 ;Initialize the counter CL with 03
MOV DI, 0120 ;Set the pointer DI to memory location 120H
MOV AH, DD ;Move immediate to register AH the value DD
XX:MOV [DI], AH ;Load the data in Al to the memory location in pointed by DI
INC DI ;Increment the pointer by 1
DEC CL ;Decrease the counter by 1
JNZ XX ;Jump to location XX if counter is not zero
INT 3 ;Exit

2. Up Counter
MOV DH, 00 ;Use DH as the start of the count
MOV CH, 03 ;Use CH as the final count value
MOV DI, 0130
MOV AH, DD
XX:MOV [DI], AH
INC DI
INC DH
CMP CH, DH ;Compare the values of registers CH and DH
JNZ XX ;and jump to location XX if they are inequal
INT 3 ;Exit

3. Use the LOOP in conjunction with the CX register
MOV CX, 05
MOV DI, 0110
MOV AH, EE
YY:MOV [DI], AH
INC DI
LOOP YY ;Loop back to YY if CX is not zero.

Try changing the register DI with SI in any of your problems. What happens ?

Additional problems using BIOS Interrupts.
e) Clear Screen
MOV AX, 0600
MOV BH, 07
MOV CX, 0000
MOV DX, 184F
INT 10H

b) MOV AX, 0004
INT 10H
MOV AH, 0B
MOV BX, 0001
INT 10H
INT 3

TUTORIAL 3
This is the last in the group of A.L programs utilizing DEBUG as a utility.

Stack operation
MOV AX, 9050
MOV CX, 479B
PUSH AX
PUSH CX
INT 3
Where is the data in AX and CX located.

e) REPEAT the above program (d) with the following additional lines of code POP BX
and POP DX at the end of the program before the INT 3.

f) Put appropriate comments for the above.

Interrupts and BIOS

2005-08-24T23:22:00.000-07:00

Test the following programs using DEBUG.
Start your program at memory address 100H.
1. MOV CH, FD
INC CH
INC CH
INC CH
INT 3

2. MOV AX, DD11
ADD AH,AL
ADD AH,AL
ADD AH, AL
INT 3

MOV BX, 0D01
ADD BH, BL
ADD BH, BL
ADD BH, BL
INT 3

BIOS INTERRUPTS
a) MOV AH,04
INT 1A
INT 3

b) MOV AH, 02
INT 1A
INT 3

For both the above programs, check the registers CX and DX to see if they have any resemblance to the date/ time functions.

-A 100
mov dx, 110
mov ah,09
int 21
int 3
-A 110
db 'Coffee Break $'

The ‘$’ marks the end of the string and is mandatory.
Then execute the program by typing
-G=100

We can save the program
-RCX 1E (CX register holds the size of the file including the data string)
-N A:\coffee.com (name of the file to be saved – must be a COM type)
-W (write the data to the disk – notice the drive light is active during save)

Addressing modes.

2005-08-24T23:21:00.000-07:00

Data transfer instructions:
A majority of these commands have the mnemonic MOV (move) to transfer data from one register/memory to another. The format of the instruction is:
MOV destination operand, source operand.
i. Immediate addressing
MOV AH, 4C (8-bit)
MOV BX, 5ABD (16-bit)

ii. Register addressing
MOV BX,CX
MOV [DI], BX

iii. Direct addressing
MOV [1000], AL
MOV CL, [1002]

The XCHG instruction can be used to swap data between two registers.
XCHG AX, BX
XCHG AL, AH

Initialize the registers AX and BX with the values 23DE and 6DF3 respectively, then run the XCHG AX, BX instruction, notice what happens.

The basic set of arithmetic instructions consists of the ADD, SUB, INC and DEC. Discussed earlier in TUTORIAL 1.

a) Direct Addressing
MOV AX, 1A2C
MOV BX, B498
MOV [1000],AX
MOV [1002], BX
INT 3

b) Register Indirect addressing
MOV AX, EC4A
MOV BX, 1000
MOV [BX], AX
INT 3
Replace the BX with DI in the above and initialize it to 1004

c) Base Relative addressing
MOV AX, 3A56
MOV BX, [1006]
MOV [BX] + 04, AX
INT 3
Replace the BX with BP in the above with the value of BP as 1020

d) Base-Index addressing
MOV BX, 1050
MOV DI, 0050
MOV AL, CC
MOV [BX+ DI], CL
INT 3
Where is the data from CL stored in memory? Check your result using DEBUG’s Display command.

e) Index Relative (Register Relative)
MOV SI, 2004
MOV AL, C5
MOV [SI+04], BH
INT3
Where is the data from BH stored in memory? Check your result using DEBUG’s Display command.

f) Base Index Relative
MOV BX , 0100
MOV SI, 2004
MOV AL, 28
MOV [BX+SI+06], AL
INT3
Where is the data from AL stored in memory? Check your result using DEBUG’s Display command.

Logical expressions
The basic logical expressions, AND, OR and XOR are available and are very easy to use.
For example:-
MOV AH, 4C
MOV AL, 43
AND AH,AL
INT 3

In the above program, replace the AND with OR and then with XOR to see the final outcome or result.

In the following program, determine the purpose of the NEG mnemonic.
MOV AH, FE
NEG AH
INT 3

Can you develop an invert (or NOT) function?
Code it here à

On the 8086 microprocessor, the AX (16-bit) and AL (8-bit) registers are the default registers for most arithmetic operations such as SUB, MUL and DIV.

For example:
a. MOV AL, 57
MOV BL, 33
SUB AL, BL
INT 3

b. MOV AL, 57
MOV BL, 33
SUB BL, AL
INT 3

c. MOV AL, 3A
SUB AL, 2C
INT 3

Repeat the above with the 16-bit registers AX initialized with values of your choice, etc.

For the multiply operation, we have to consider that a 8-bit x 8-bit produces a 16-bit result. So for this the AH register should be cleared (set to 0) to store the higher order byte after the multiply.

For example:
d. MOV AL, 57
MOV AH, 00
MOV BL, 07
MUL BL
INT 3

Verify your result manually.
Can the above program be shortened ?

For 16-bit operations, the DX register has to be cleared to store the higher order word.
For example:
e. MOV AX, 615A
MOV BX, 0003
MUL BX
INT 3

The divide behaves in a similar concept as the multiply, except that the remainder is stored in AH register for an 8-bit operation.
For example:
f. MOV AL, 57
MOV AH, 00
MOV BL, 07
DIV BL
INT 3

Again as in the case of a 16-bit divide, the remainder is stored in the DX register.
It is vital to clear the DX register before you execute the code otherwise you may obtain some unpredictable results.

For example:
g. MOV DX,0000
MOV AX,0457
MOV BX,0002
DIV BX
INT 3

In most cases, the result of addition and subtraction may produce a result that is not in decimal but instead a hexadecimal value is obtained. In order to rectify this problem, there are 8-bit calculations that can produce a decimal-like output. This is through the use of the Decimal Adjust after Addition (DAA). This has to be used in conjunction with the AL register only and is in the Packed BCD format.

For example:
h. MOV AH, 05
MOV AL, 07
ADD AL,AH
DAA
INT 3

The same applies for the subtraction, in which the operand must be less than 100 in a packed BCD format.
i. MOV AH, 08
MOV AL, 37
SUB AL, AH
DAS ; Decimal Adjust after Subtraction
INT 3

The results of calculations to be displayed on the screen have to be converted into an ASCII format to be recognized. Just as in the previous examples, the mnemonic Ascii Adjust after Addition (AAA) is used in conjunction with the AL register.

j. MOV AH, 00
MOV AL, 07
ADD AL,05
AAA
INT 3

k. MOV AH, 00
MOV AL, 12
SUB AL,05
AAS
INT 3
Research this more in detail and also on the AAD and AAM mnemonics.
Exercises
Initialize memory locations 0132 and 0133 with the values 03 and 06 respectively. Then enter the following program, run and locate the resulting data in memory.

i. MOV SI, 0130
MOV DI, 0150
MOV AH, [SI + 2]
ADD AH, [SI + 3]
MOV [DI + 0E], AH
INT 3
Where is the result stored?

ii. MOV SI, 0130
MOV DI, 0140
ADD SI, 02
MOV AH, [SI + 0]
ADD AH, [SI + 1]
DEC DI
DEC DI
MOV [DI + 0C], AH
INT 3
Where is the result stored?

iii. MOV AX, 2000
MOV DS,AX
MOV SI, 0130
MOV DI, 0150
MOV AH, [SI + 2]
ADD AH, [SI + 3]
MOV [DI + 0E], AH
INT 3

Where is the result stored?

iv. MOV AX, AA65
ADD AX, 66AA
ADC AX, 1099
INT 3

What does the instruction ADC undertake? Verify your result.

What is the equivalent instruction when we perform a subtraction?

Introduction to Debug

2005-08-24T23:19:00.000-07:00

INTRODUCTION
Summary of DEBUG instructions.
The following is a list of frequently used DEBUG instructions obtained from the books:
The 80x86 IBM PC and Compatible Computers ( Volumes 1 & 11)
By Muhammad Ali Mazidi & Janice Gillispie Mazidi
ISBN 0-13-698938-1 Prentice Hall

IBM PC Assembly Language and Programming (5th Edition)
By Peter Abel
ISBN 0-13-031916 Prentice Hall

A - Assemble <> “ The location of your program “
E - Enter <> <>
R - Register name <> “ Examine or alter the contents of the Registers”
T - Trace < =Start Address > <>
U - Unassemble <> <> “ Display program
format/code “
G - Go OR Execute < = Start Address > <>
F - Fill <> <> data
Q - Quit
For other Commands please refer to the above book or DOS reference book.

· NOTE : For most of your example programs listed below, please ensure that your programs end with an INT 3 statement otherwise you may experience unforeseen results. The prompt in DEBUG is a ‘-‘. All numeric data is in the Hexadecimal format.

Command line instructions
- R CX
CX 0000 <>
: FFFF
- R CX
CX FFFF

Now type in R

For the following examples try examining the registers with the Trace command. Record your results for further discussion in class.
-A 100
MOV AX, 123A
MOV BX, DC7E
INT 3

Use the D (display) command to examine the memory locations 100 to 106
Using the following
-D 100 106

Which displays the following:-
0B23:0100 B8 3A 12 BB 7E DC CC .:..~..
segment : offset combination of instruction op-codes and data ASCIIcharacter

Use the E (enter/edit) to change the following data.
-E 101
0B23:0101 3A.7B (space bar) 12.35

Then use the U (unassemble) command as:
-U 100 106
0B23:0100 B83A35 MOV AX,357B
0B23:0103 BB7EDC MOV BX,DC7E
0B23:0106 CC INT 3

Try and change the values of in memory locations 104 and 105 to 11 and 55 respectively. Notice any changes

Change the value in memory location 103 to B9. Explain what happens.
(Note: if you have any problems start from the beginning) i.e (i)

i) MOV CX, 198D
MOV BP, CX
MOV ES, CX
INT 3

ii) MOV AL, 12
MOV BH, 2A
ADD AL, BH
INT 3

iii) MOV DH, 1269
INT 3

iv)MOV ES, 114E
INT 3

Enter the following
-D 40:0 F
0040:0000 F8 03 F8 02 E8 03 E8 02-BC 03 78 03 78 02 C0 9F ..........x.x...

This provides the BIOS data area corresponding to the COM and LPT ports.
The first four words are for the COM ports (1 to 4). (03F8 & 02F8 for COM1&2)
The second four words show the parallel ports. (0378 for LPT1)

Deactivate all the Lock functions (CAPS, NUM and SCROLL)
-D 40:17 18
0040:0010 00-00
then press the CAPS Lock
-D 40:17 18
0040:0010 40-00
and then press the SCROLL Lock
-D 40:17 18
ß----record your result here
and then press the NUM Lock
-D 40:17 18
ß----record your result here
type D 40:49
the first byte contains the current video mode (such as 03 for color)
the second byte is the number of columns on the screen (50H = 80)
the number of rows is at location 40:84H

The ROM BIOS date is at location FFFF5 H, in order to see this key in
-D FFFF:5
ß----record your result here
If you know the actual machine codes then you can enter the data directly by the following method :-
-E CS:100 B8 34 12 05 11 2C CC (and press Enter)

then key in the following
-U 100 106
you should obtain the following outcome :-
0B23:0100 B83412 MOV AX,1234
0B23:0103 05112C ADD AX,2C11
0B23:0106 CC INT 3
(Note: if you do not have the machine codes for the 8086, do not panic as this conversion is done for you when you run the A (assemble) command)
CS indicates the Code Segment. This is where all your program codes are written/stored.

The video memory area is at B800 and we can fill this with certain patterns, provided we have the ASCII character value. Try the following :-

-F B800: 0 FF 2A
-F B800: 0 LFA0 03 16
FA0 is equal to 4000 locations
03 is the pattern for ♥
16 is the attribute, brown on blue background
-F B800:0 L8a0 06 18

Finally try to enter a string
-A 100
0B23:0100 DB 'My name is .....’
0B23:0111

-D 100 111
0B23:0100 4D 79 20 6E 61 6D 65 20-69 73 20 2E 2E 2E 2E 2E My name is .....

Data Communication Lab

2005-08-24T02:49:00.000-07:00

Lab 1 : Introduction to Internet

CSC187 Lab Tutorial

2005-08-24T02:32:00.000-07:00

Lab 1 : Introduction to Computer/Digital Information
Lab 2 : Microprocessor
Lab 3 : Introduction to Debug
Lab 4 : Interrupts and BIOS
Lab 5 : Counter, Loop and Stack
Lab 6 : Assemble, link and debug
Lab 7 : Sample File
Lab 8 : Srting Operation
Lab 9 : Sorting Numbers
Lab 10 : Serial Communication
Lab 11 : Music.ASM to EXE
Intel 80x86 Instruction Set

The 80x86 Family Lab Exercise
Chapter4 Debug
Chapter 5 (Programming Technique)
Chapter 6 (.com & .exe) MASM611 MASM611 Readme File
Chapter 8 (Programmed I/O)
Chapter 9(Interrupt and DMA)
Chapter 10 (Data Communication)

Introduction to How PCI Works

2005-08-24T01:51:00.000-07:00

Introduction to How PCI Works
Get On the Bus
Quick History
Along Comes PCI
Plug and Play
How It Works
All aboard the PCI Express
Lots More Information
Compare Prices for PCI

System Bus

2005-08-24T01:33:00.000-07:00

Definition of System Bus
Inside a Microprocessor
Get On the Bus

Introduction to How BIOS Works

2005-08-24T00:50:00.000-07:00

Introduction to How BIOS Works
What BIOS Does
Booting the Computer
Configuring BIOS
Updating Your BIOS
Lots More Information
Compare Prices for BIOS

Binary System

2005-08-24T00:31:00.000-07:00

Binary Arithmetic
Addition
Subtraction
Multiplication
Division
Notes

2's Complement Representation for Signed Integers
Definition
Calculation of 2's Complement
Addition
Subtraction
Multiplication
Division
Sign Extension
Other Signed Representations
Notes

Binary Coded Decimals (BCD or "8421" BCD)
Encoding
Packing a Two-Byte BCD
Converting between Decimal and BCD
Converting between Binary and BCD
Addition
Subtraction
Unpacked Multiplication
Unpacked Division
Other Decimal Codes
Other Resources

Converting Between Integer Representations
Comparison of Representations
Either Hexadecimal, Binary or Octal to Decimal
Decimal to Binary
Decimal to Hexadecimal
Decimal to Octal
Binary and Hexadecimal
Binary and Octal

ASCII
Control Codes
Extended Character Set -- Macintosh
Extended Character Sets -- PC
Standard Character Set

2005-08-22T20:27:00.000-07:00

Introduction to How PCs Work
On the Inside
Connections: Input/Output
Connections: Ports
Connections: Internet/Network
From Power-up to Shut-down: BIOS
From Power-up to Shut-down: Operating System
The Future: EUVL Chipmaking
The Future: DNA and Quantum
The Future: Off the Desk
Lots More Information
Compare Prices for PCs

Introduction to How Operating Systems Work

2005-08-22T19:11:00.000-07:00

Introduction to How Operating Systems Work
The Bare Bones
What Does It Do?
What Kinds Are There?
Wake-Up Call
Processor Management
Memory Storage and Management
Device Management
Interface to the World
What's New
Lots More Information
Compare Prices for Operating Systems

How can I optimize the Windows 2000/XP/2003 virtual memory (Pagefile)?

TCP/IP Utilities

2005-08-09T19:44:00.000-07:00

Table of Contents
ARP
Nbtstat
Netstat
Ping
Route
Tracert
Winipcfg
Arp
ARP stand for Address Resolution Protocol. This provides IP to Ethernet addresses. Each hardware card has an address coded in. This allows deletion and addition to the ARP cache.
The switches to be used can be obtained by just typing arp at a DOS command prompt.
Some more ARP information
Back to Top
Nbtstat
This is a very useful little tools if networked and/or using Win servers or Lmhost file. It displays TCP/IP connections using netbios. The switches to be used will be shown if typing nbtstat from the command prompt.
Here is an interesting little example of how it may be used:
If you and your friend have WIN servers inserted in your network or connection setup and have log onto network checked then the Wins server will register you when you log on. If the other person's computer name is Alpha then typing Nbtstat -a Alpha will provide that computers IP address.
Nbtstat may also use the lmhost file. Typing nbtstat from the command prompt will provide a set of switches.
Nbtstat - WINS - LMhost is oriented towards relating Computer Names (netbios names) to IP addresses and is very useful on any network were IP addresses are dynamic. The Computer name must be unique.
Some more nbtstat information
Back to Top
Netstat
This utility provides the connection both the local and remote, ports and the state of the connection. It has several switches which maybe found by typing netstat /? from the command prompt.
It provides the IP addresses and the ports of the remote computer(S) to which the socket is connected. If a port has not been established it is indicated by a *.
It shows the the port numbers as well as IP address for the local computer.
It provides the type of protocol being used for the connection(s).
It provides a status of the connection. Is it established ?? is it closed ?? or is it waiting ?? and more.
Some more netstat information
Back to Top
Ping
This is a simple diagnostic tool to verify connection and also used quite frequently as a troubleshooting tools. The available switches can be obtained by typing ping from command prompt.
If Name resolution fails, meaning your connection doesn't seem to work properly; then ping may be used as follows to try to identify the problems:
Ping 127.0.01 That is yourself and will indicate that the networking on your computer works.
Ping a known address like ping 207.159.136.230. That is my web site here. If it works then you have a good Internet connection.
Try next ping www.hildrum.com if it does work everything is fine. If it does not you may have name server problems. There are also Winsock duplications and problems which might cause this to happen.
Some Ping Examples
Back to Top
Route
Type Route at the command prompt to see the options (switches).
This command is very useful if using networking. It allows you to view and manipulate the routing tables. It is a very useful tool for diagnosing and modifying networking routing issues
Some more information and examples
Back to Top
Tracert
This is a utility which allows you to see the route taken by packages from yourself to a destination. It also show the time it takes. It can also be used to determined the IP address of a service were you only know the name.
Some more info
Back to Top
Winipcfg
A very useful little utility. Use Start ---->Run and type in winipcfg. It will tell you your present IP address and your subnet mask. If you click "more info" it will also provide the DNS (Domain names servers) and WINS servers if you have any.
More info on winipcfg

UDP

2005-08-09T19:43:00.000-07:00

Lesson: All About Datagrams
Some applications that you write to communicate over the network will not require the reliable, point-to-point channel provided by TCP. Rather, your applications might benefit from a mode of communication that delivers independent packages of information whose arrival and order of arrival are not guaranteed.
The UDP protocol provides a mode of network communication whereby applications send packets of data, called datagrams, to one another. A datagram is an independent, self-contained message sent over the network whose arrival, arrival time, and content are not guaranteed. The DatagramPacket and DatagramSocket classes in the java.net package implement system-independent datagram communication using UDP.
What Is a Datagram?
A datagram is an independent, self-contained message sent over the network whose arrival, arrival time, and content are not guaranteed.
Writing a Datagram Client and Server
This section walks you through an example that contains two Java programs that use datagrams to communicate. The server side is a quote server that listens to its DatagramSocket and sends a quotation to a client whenever the client requests it. The client side is a simple program that simply makes a request of the server.
Broadcasting to Multiple Recipients
This section modifies the quote server so that instead of sending a quotation to a single client upon request, the quote server broadcasts a quote every minute to as many clients as are listening. The client program must be modified accordingly.

SMTP Session Emulator

2005-08-09T19:41:00.000-07:00

On-line interactive demo/tutorial
http://www.ostrosoft.com/smtp_component/smtp_demo.asp

Telnet Tutorial

2005-08-09T19:39:00.000-07:00

What is telnet?
Why would I need it?
How is it different from FTP?
Telneting to your account through the Control Panel
Telneting to your account through other software

Learn TCP/IP with video

2005-08-09T19:37:00.000-07:00

Introduction
Introduction to TCP/IP
TCP/IP and OSI Models
Connection Controls and Windowing

IP Addressing
What is an IP Address?
ANDing Addresses
Classes Solutions for Classes A Binary Lesson
Solutions for Binary
Subnetting
Borrowing Bits Solutions for Borrowing
Subnet Numbers Subnet Masks Solutions for Masks
Address Ranges
Solutions for Ranges Practice 1
Solutions for Practice 1
Practice 2 Solutions for Practice 2
Windows Calculator
IP Version 6

Installation of the Protocol Suite
Windows 2000 Professional (W2K)
Windows NT 4.0 (NT 4)

LearnTCPIP

2005-08-09T19:34:00.000-07:00

Online learning TCPIP with powerpoint and voice

New Version 3.0 Network Technologies Educational Series Requires Internet Explorer 6.0+ or Netscape 7.0+ and Windows Media Player 6.4+ (System Requirements Page)
The LearntoSubnet™.com Lecture Series "A Free, Lecture-based Educational Course on IP Addressing and Subnetting."
How the OSI Model Works ™.com"A Free, Lecture-Based Presentation on How the OSI Model Works"
How TCP/IP (Networking) Works ™.com Lecture Series "A Lecture-Based Presentation on How TCP/IP Networking Works!"
How The Internet Runs ™.com"A Free, Lecture-Based Presentation on How the Networks of the World Interconnect to Create the Internet!"
How DNS Works™.com"A Free, Lecture-Based Presentation on How the Domain Naming System Works!"
License -- Usage Guidelines
Tips: How to Use This Site
System Requirements and Downloads
TCP/IP and Certification Resources

Computer Protocol Tutorials and Resources

2005-08-09T19:33:00.000-07:00

HTTP Tutorials and Resources
ICMP Tutorials and Resources
IMAP Tutorials and Resources
MIME Tutorials and Resources
POP3 Tutorials and Resources
SMTP Tutorials and Resources
SNMP Tutorials and Resources
SOAP Tutorials and Resources
TCP/IP Tutorials and Resources
UDDI Tutorials and Resources
UDP Tutorials and Resources

Domanin Name Server DSN

2005-08-09T19:28:00.000-07:00

Just added: www.DNSstuff.com Forums! Named to PCMag.com Top 100 Sites for 2005, Computing Category! This site has many DNS and networking tools for network administrators, domain owners, users of DNS hosting services, etc. There is no cost for using this site. You are free to link to this site. If these tools are useful and you need anti-spam or anti-virus software for your mail server, please consider looking at the excellent Declude products. If you want your email filtered for you, please consider Spam Soap. Thanks!

http://www.dnsstuff.com/

Business Data Communications

2005-08-09T19:26:00.000-07:00

Welcome to the Website for William Stallings Business Data Communications, Fourth Edition. This highly successful book offers students and professionals thorough coverage of data communication fundamentals that are key to network and information management. Best-selling author, William Stallings, provides authoritative and up-to-date coverage of the key issues for the business student, including high-speed networks, ATM and TCP/IP, as well as the use of the Internet, intranets, and extranets.
This fourth edition presents concepts in a way that relates specifically to the business environment, while simultaneously providing the reader with a solid understanding of the technical foundation of business data communications.
This Website provides the text's Preface, Table of Contents, Sample Chapters (1,2 & 3), and reviewers' quotes. We hope you will find it useful.
The Prentice Hall Computer Science Team
http://cwx.prenhall.com/bookbind/pubbooks/stallings/

Introduction to Microprocessor

2005-07-26T22:30:00.000-07:00

From Howstuffwork
Introduction to How Microprocessors Work
Microprocessor History
Microprocessor Progression: Intel
Inside a Microprocessor
RAM and ROM
Microprocessor Instructions
Microprocessor Instructions: Assembly Language
Microprocessor Instructions: ROM
Microprocessor Instructions: Decoding
Microprocessor Performance
Microprocessor Trends
Lots More Information
Compare Prices for Microprocessors

Intel : The Journey Inside
Introduction to Computers
Circuits and Switches
Digital Information
Microprocessors
The Internet
Technology and Society
Glossary

Instruction Pointer
CPU Design

OPNET IT Guru Simulation Lab Exercises

2005-05-24T01:39:00.000-07:00

OPNET IT Guru is the industry’s premier network modeling and simulation software. IT Guru allows you to model an existing or planned network and then run simulations on the base model and on scenarios involving potential design changes to the base model. Simulation can shed light on design alternatives without the cost of building several real networks. OPNET IT Guru has a module, the Application Characterization Environment, which can be used to perform analyses on application quality of service parameters. The last lab exercise introduces ACE.

Professor Raymond Panko and OPNET have jointly created seven hands-on lab exercises that students can perform. Students will not actually build new models, but run simulations on pre-configured projects and modify certain parameters to reflect different design alternatives.

The lab exercises are tied to the book's content but are written so that you can introduce each exercise when you feel that it is appropriate.

http://panko.net/OPNET/OPNET%20IT%20Guru%20Simulation%20Lab%20Exercises.htm

Lab Manual
http://www.ccse.kfupm.edu.sa/~mibuhari/ics432/labs/Simulation-ITGURU.doc

Download OPNET Free Software (Academic Version)
http://www.opnet.com/services/university/itguru_academic