The disk should autostart when you insert in a CD-ROM drive. If this does not happen, double-click on the index.html file in the root directory. This file contains detailed instructions and help.

When I use Microsoft CodeView to display 32-bit registers, why do zeros mysteriously appear?

As you've noticed, when the highest bit of the color attribute is set, the background color becomes brighter (or brown becomes yellow). You can get the blink attribute to work if you run your program in a Command Window and then press Alt-Enter to switch to full-screen mode while the program is running. On the other hand, if you switch to full-screen mode first and then run your program, the blink attribute doesn't work--the highest bit simply brightens the background color.

The Help files supplied with MASM are an excellent reference, not only on assembly language syntax, but also on using the Assembler (ML.EXE), CodeView, the Linker, and other utilities. You can access help from the Programmers Workbench (PWB.EXE), from CodeView (CV.EXE), or from a stand-alone help program named QuickHelp (QH.EXE). To run QuickHelp directly, double-click on the batch file named runQH.bat in the C:\Masm615 directory.

When Windows runs a 16-bit MSDOS application, it needs a certain amount of environment space for temporary variables (such as PATH and TEMP). Click here to learn how to increase this space.

Microsoft no longer publishes the printed manuals, but HTML versions of the manuals can be found on Web sites belonging to Randall Hyde and Kevin Lillis.

Windows ME has an installable option that permits the use of a DOS prompt. Please see their help files for an explanation of installing this. Also, you might want to read article Q179644 in the Microsoft knowledge base (http://www.msdn.microsoft.com).

First of all, never run a nontrivial program without a debugger. There are too many things that can go wrong! In Microsoft CodeView, for example, you can trace your program using the F8 and F10 function keys, watch the registers and stack, and in general be aware of everything your program does, statement by statement. It's surprising how often beginning students ignore this advice, much to their frustration later. Experienced programmers, on the other hand, develop excellent skills with CodeView and other debuggers.

Here are some of the most common causes for a wayward assembly language program:

1. The stack has been corrupted because of a mismatching sequence of pushes and pops, causing a RET instruction to go to the wrong location. To catch this error, you must press F8 on the RET instruction and note carefully the location to which it branches.
2. A loop doesn't stop, possibly because ECX or some other loop counter has been altered inside the loop. Or, perhaps a conditional jump instruction that was supposed to exit the loop was never taken.
3. Machine code in the code segment has been overwritten by data, possibly because the value of an index register (such as ESI, EDI, or EBX) is incorrect. This is quite difficult to detect, unless you switch the source window options in CodeView to the Disassembly option. When you see garbled instructions in place of the code you know you wrote, it's clear that the code has been corrupted

Can a procedure be called using a register name as the target label?

Easily! For example, we can load EDX with the offset of MyProc and call the procedure directly:

     mov edx,OFFSET MyProc

     call edx

You can also call a procedure indirectly, as is done on page 209. EBX + 1 points to a memory operand containing the offset of a procedure:

     call NEAR PTR [ebx + 1]

Why does my browser display an error message when trying to follow your link to Microsoft's Assembler Reference page?

GetMseconds calls a Win32 API function named GetLocalTime (see page 406). This function is accurate to 10ms under Windows NT/2000/XP, but it is only accurate to about 50ms under Windows 98/Me. The GetMseconds function in the Irvine16 library accomplishes its task using calls to INT 21h, and is also accurate to about 50ms.

You may have installed Windows XP on top of an older operating system such as Windows 98. In that case, your autoexec.nt and config.nt files may have out-of-date information. Check out Microsoft Knowledge Base Article 314495, entitled "How to Troubleshoot 16-bit Windows Programs in Windows XP".

I'm impressed! Next, try: 1) Windows Assembly Language and Systems Programming by Barry Kauler; 2) Graphics Programming Black Book by Michael Abrash. They're both fantastic.

Absolutely not! It would not be ethical for me to do so.