SYMDEB

The MS-DOS Encyclopedia has a sample TSR, snap.asm. I built and ran it,
but the PC locked up. SoftICE can debug TSRs, but that's overkill if the
bug is in the transient setup part, before going resident. In that case,
tools like debug.exe will do.

In DOS Internals, Chappell says he likes symdeb.exe. I didn't know much
about it, but I wanted to learn more.

It's similar to debug.exe, but enhanced for symbolic debugging. Still
has a primitive interface, but that's good for conserving memory. Takes
less than 40k.

4.00 is the final version of symdeb.exe. It comes with MASM 4.00. But
MASM 4.00 has no /Zd switch, so you don't get debugging info in the .OBJ
file. At that point in history, symbolic debugging only worked with the
Microsoft high level language compilers.

MASM 5 has the /Zd switch, and I wondered if that would work with symdeb
4.00.

I found that mapsym won't create the .SYM file right unless you have at
least one public symbol in your .asm source. So I made the entry point a
public symbol, and then it all worked, like so:

masm /Zd snap;
link /li /m snap;
mapsym snap
symdeb snap.sym snap.exe


As for the PC lockup bug, it was in the transient part, so I was able to
find it without using SoftICE.

To avoid tedious typing, I copied SNAP.ASM from the MSLIB 1.3 CD-ROM.
But it has a nasty typo, which was corrected in the book. Seems strange
that the book is right and the disk is wrong, but that's how it is.

Now snap.exe works. No more PC lockup.

Do you mind posting the diff code?

I deleted my work, but the diff is small.

See GetDOSVersion PROC near line 908. They set up the INT21 call wrong
by moving 30h to AX. It should be AH, not AX.

Obvious typo, easy fix.

Hi,
Just for comparison, I think most others would rather use
OpenWatcom's WD (probably with JWasm):

* http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/devel/c/openwatcom/1.9/extras_japheth-wd/

Ladsoft (CC386, OrangeC) also has GRDB debugger, and you can use
his MKSYM util or VALX linker for symbolic support:

* http://ladsoft.tripod.com/grdb_debugger.html

I speak for myself. Chappell speaks for himself.

YOU speak for "most others"

Loser.

Hi,

On Tuesday, April 14, 2020 at 9:44:23 PM UTC-5, T. Ment wrote:
Did I miss something? I know you have issues with, well, everybody
and everything, but ... this was a purely technical response with
obvious links to related alternatives. Is that offensive to you??
(The devil is a loser; however, I did nothing to you.)

You claim to be a Christian, but you don't act like it.
I'd rather not raise any ire with others by spamming the Bible
here over dozens of off-topic messages. However, you should
definitely re-read some parts:
Luke 18, Matthew 5, 1 Corinthians 1.

However, I recognize your M.O. You'll just snip the irrelevant
part of the message and quip rudely back in response. It's
not clever, it's not wise, and frankly, it's a waste of time.
You seem very confused.

Unlike you, I don't have the luxury of arguing unjustly.
I have to act responsibly, if at all possible. Therefore,
I have to pray for you (see Matthew above). It's not that
I foresee that others care about my example, but it's
neither useful nor justified to argue over such nonsense.

"most others" It's quoted and you still miss it.
You claim to know what "most" people want, as if you're the leader of
some moral majority.

You don't have the guts to speak for yourself alone.

Coward.

Hi,

On Thursday, April 16, 2020 at 9:43:16 AM UTC-5, T. Ment wrote:
Is this legitimate criticism? Did you really not understand what I was saying?

It's a symbolic debugger that other people use. It's freely available
(open source). That's all.
As Christians, we must respect just authority, yes. So not every
random opinion is valid, no.

However, I wasn't imposing or promoting anything here, just passing
along some links. If you haven't tried them yet or they don't fit
your needs, that's okay.
It's not my fault if you're angry and dejected over trivial matters.
Unjustified anger is not strength, and it's certainly not virtue.

> Coward.

* https://en.wikipedia.org/wiki/Seven_gifts_of_the_Holy_Spirit#Fortitude

Yes you were, liar.

I didn't ask for alternatives to SYMDEB, or what "most others" think.
You started that fight all by yourself.

I knew you were trouble when I saw your long winded, paranoid tirades
against Jack. People like you can't shut up when they're wrong.