Wanted: old DOS debugger s-ice v1.03 & v2.1
 

As I remember well, I teached myself assembly language
by studying DOS viruses.
Now I want to reactivate my favorite debugger s-ice under
DosBox or Bochs so that I can debug old viruses, but I found
that s-ice v2.8 crashed under DosBox & Bochs. Bochs seems
good to start s-ice v2.8, yet if I press F8 to step, it crashes.
I have tried debugging s-ice by using both of Bochs' internal
debugger and Ollydbg which debugs Bochs, and found that
s-ice crashed at address cs:0x6F2E. When s-ice starts, I
LDR some exe say hello.exe, then I press Ctrl+C in Bochs
console window, and command "vb cs:0x6F2E" and further
command "continue" , finally I press F8 in s-ice, the breakpoint
just set will be triggered, now, if I command "s" to single step
in Bochs console, IP will be set to the entry point of an exception
handler instead of the first instruction of the far call located at
cs:0x6F2E.
Though Bochs is open source, yet I felt much hard to
locate the bug, further more, s-ice's "bpmb addr x" & "bpint"
commands do not work in Bochs.
I want s-ice 1.03 & 2.1 which were reported to work under
DosBox, so that I can make a comparing with 2.8.
Thank you.

dosbox author's suggestion is to use dosbox internal debugger

https://www.vogons.org/viewtopic.php?t=15940

Finally, I found DOS s-ice v2.0 on the internet, yet
my experiments proved that the old s-ice could not
work under DosBox or Bochs, the so-called good
working report is actually a fake.
If anyone is interested in this very old stuff, pls
download it at the following link:
http://blog.cnstock.com/UploadFiles/...2051358848.zip

Is there anybody to give me a clue to making s-ice work under Bochs?
If I give up Bochs, any suggestion to a substitution for Bochs?
Thanks.

If your goal is to get softice working, I think it would be most practical to create a virtual machine with Windows 98, or the latest supported by your target application, and run it from there. You also have the alternate option of using the ring 3 debugger TRW2000.

My goal is not for sice working in Windows, but rather in DOS.
Because I want to use sice as a best choice to teach my students to
debug old DOS viruses.

I don't judge or anything. But are you sure they need it? As I remember my university course about viruses and it was about DOS. It was like I stepped into a time machine and travelled ~20 years back. It was a completely useless and outdated experience.

In that case, you can use an ms-dos virtual machine. They would have the full operating system experience without the hassles and limitations of dosbox or bochs.

However, like Archer, I question the practicality of this teaching approach. A "back in my day, we did it this way" approach to teaching, though it certainly will give students an appreciation for technological advances, may not carry over very well to modern approaches. It would be a similar concept to teaching a Spanish major Latin prior to teaching him Spanish because its roots are founded in Latin. It doesn't seem very practical. This is merely my opinion though.

It is also important to note that depending on your country of origin's adherence to the Digital Millennium Copyright Act(DMCA), having students use SoftIce, a program classified as commercial abandonware, is a legal gray area. Legally speaking, it is still considered piracy by definition.

Though, DOS is too old, yet
I believe, to master the concept of interrupt, DOS is still a best choice;
And, to practice the hooking techique, DOS is unparallable to Windows or Linux,
because it is simple;
Surely, the course is not limited to DOS, Windows and Linux are also
concerned.

As said Archer:"As I remember my university course about viruses and it was about DOS. It was like I stepped into a time machine and travelled ~20 years back. It was a completely useless and outdated experience."

you said:"Because I want to use sice as a best choice to teach my students to
debug old DOS viruses."
It's a no way to teach them oldies,think that students need to learn actual methods to become the next generation of coders,reverse engineering.

If you wish to teach BIOS interrupts you still dont need sice. Yes modern Windows hides these though they are still there. Just write assembler, compile it and copy the machine code to sector 0 of a USB disk and MBR boot it though you have to load more sectors if you want more than 256 bytes. Can write this into the asm just look how any MBR asm works. Then you could load sector 1 and start running any asm.
Now you taught BIOS interrupts, master boot area, boot load process, real mode assembler, etc.

Of course you can also do it in a ISO booted VM even better.

Debugging requires an in circuit emulator in this context so instead just use lots of int21h calls to write messages.

The asm construction and writing raw sectors to the USB or ISO and the fake MBR are all real work but I'd love to see this idea on github just for fun and learning.

Even me have try to run Softice for dos in an emulated environment, but I always failed.
Wmvare is able (with some limitations) to run Softice for window, but not softice for dos :-(

best DOS debugger I've ever seen is
avputil.com (.com file, not a site)
36.6 KB in size
amazing stuff

debug.exe from old windows too

Check http:// old-dos. ru/index.php?page=files&mode=files&do=list&cat=229&id=5

TRW 2000
 

TRW 2000 was the best debugger for me for DOS applications. We used to load some script to fool microcosm protection ccmove.exe once we had an valid license TR really helped at that time. Its an cool debugger.

Nice old days now vaporised.
Sope!

Have you made SoftIce run on Windows XP inside Vmware?

It was some years ago, but yes I remember xp emulate with wmware ( i failed with Virtualbox) Softice 4.05 if i good remember, but not x dos..

Nowadays you can use debugger built-in in DosBox. It is useful and comes with full source, so you can modify it as you need.

Or going back in time if you have 9900 Euros lying around, you can buy an 80186 In-Circuit Emulator or learn all about it here: https://ceibo.com/eng/products/ds186.shtml

That brings back some memories. I looked into getting one of these to develop an access control system many moons ago. But the accountants said no, so I had to make do with plenty of flashing LEDs and print statements :eek:

It would be an amazing tool to experiment with or toy to play with, but alas the cost is just too ridiculous.

Its amazing that the latest I could find are for 386 processors.

I guess the hardware people are using different tools and techniques to do development. Probably we are at the point that software emulators and VMs and such are more than adequate. And so an ICE has become more or less an expensive part of history. Doubtful an ICE for modern x86 processors will ever be made.

A good tool was the Action Replay, they released a couple of versions for PC (DOS and Windows 95/98).

The Amiga version was much more advanced, a real hardware debugger.

alas they never sold it like amiga's one,bad implemented,isa card and buggy as hell afaik.

DOS/Win9x viruses? all the good ones were by z0mbie and vecna =>

@Fyyre ... you know stuff :)
Still today reading all the stuff released by z0mbie would be sooo useful for many people,

Vecna also produced very good code, but Z0mbie used to released weird and interesting stuff (as the zip cryptor he used in his
releases), imho.
With these people you learn to think as a reverser, yes you do specific things, but you learnt how these guys solved complex problems in optimum ways, many time hackish, but sooo much fun, and also usable in modern times in many different problems.

The HPVA scene was a incredible learning resource for many people, I specially remember many Virii zines as A29, 40hex or Vlad magazines. I recommed you guys download some online collection or repo of virii zines ,still many things online, get it before is impossible to get. Btw, I maintain a huge DOS virii collection, also a DOS CRACKMEs collection, all those are extensively search online and scrapped and collected for any site I've could found (if you have stuff to add, make me happy and send me links :D )

My favourite stuff to research were mutation engines, cryptors, tracers, etc
Maybe many of you remember coming to this same page to get last versions of Unp unpacker, or the many packers released by ROSE, Stone, etc It was a very prolific time, maybe people coded packers and protectors, other people created specific deprotectors or even better, generic unpackers, using VMs a a lot of advanced stuff.

It were good times, I think I keep collecting DOS stuff for my collection because I learned all through these things (and not coding stupid crud Clipper vertical programs :D:D)

Hi an0rma1,
is your collection public or otherwise reachable on the internet?

You refreshed my old memories.
ROSE (Ralph Roth) and Stone (The UCF one?) are my friends in DOS time.
I coded a simple protector called FSE at that time as well.
So, I was more focus on protection, not virii things.

@zenix: FSE was one of the most advanced protector from its era :D I remember it painfully :D I got versions from 0.4 to 0.76c, also I have from you a Trap protector remover. Yes I was not interested in Virii per se, just to know more about coding, techniques, etc.
Also, did you know Rose keeps releasing DOS stuff all these years? I got a huge archive of all his releases until today.

@ethereal: I uploaded here a pair of times these last years, but it's constantly updated, I can upload what I have know, I can upload these: DosExe collection, a huge Dos Compilers collection (I am sure this is the biggest one you can find), a Floppy copying/managing collection (also pretty unique stuff here), and some smallers ones.

All of these is previous work to a general DOS collection I am planning.

If you want I can upload those.

Edit: done a quick pack and uploaded in Community tools, have fun.

Public here:

@an0rma1 No, I do not know ROSE is still releasing DOS stuffs.
I lost my computers, source codes and collections in the Taiwan 921 earthquake (1999).
Luckily, my families survived from it.

[QUOTE=ZeNiX;120773I lost my computers, source codes and collections in the Taiwan 921 earthquake (1999).
Luckily, my families survived from it.[/QUOTE]

it would be bad taste to post a "thanks" for this.
i'm living onto an area that may make it again,kind of century earthquake where i can't even think of the future.
for another reasons I've lost many collections,archives,
greets.

I am sorry to hear this.
I lost nearly everything that I owned and cherished, in a natural disaster around 2013-2014. Computers, property, everything.
I know how it feels to lose everything. :(
It took me almost one year to find the strength to get up back on my feet and try to start afresh again.
I was not that lucky. I lost a family member too at the time.

While most of the files were re-downloadable, the psychological trauma was very great.
I hope that such things should not happen to anyone...