3 ms·
Ooh, I used to play around a lot with DEBUG.EXE when I was like 12. To this day, almost without looking at the keyboard, I can enter some assembly that enters M
by nathell 4y ago
Ooh, I used to play around a lot with DEBUG.EXE when I was like 12. To this day, almost without looking at the keyboard, I can enter some assembly that enters Mode 13h and draws stuff on screen.
These days, I sometimes play with it to debug a pet project (Lithium, an x86 assembler and toy Lisp compiler targetting bare metal and .COM binaries, written in Clojure). And sometimes I discover things I wasn’t aware of: https://blog.danieljanus.pl/2014/04/06/dos-debugging-quirk/ https://blog.danieljanus.pl/2014/04/06/dos-debugging-quirk/
- distcs 4y agoAre you running on QEMU? How do you make t stop after every step? And why did t did not stop at mov bp,sp for you? I can't get tracing to work at https://copy.sh/v86/?profile=msdos https://copy.sh/v86/?profile=msdos Modified OP's code to add more steps to see some stepping through but T makes the program run all the way to termination - https://i.imgur.com/hiYeC2x.png https://i.imgur.com/hiYeC2x.png
- blueflow 4y agoI think the CPU emulator of that website is just buggy
- distcs 4y agoDo you know why in nathell's link the first t does not stop at mov bp,sp? It stops at other lines but not that one. Could that be a buggy emulator too?
- nathell 4y agoI tried in DOSBox. It was years ago, so I don’t remember all the details. Maybe it’s a DOSBox issue that has since been fixed!
- nathell 4y agoLooks like v86 doesn’t implement the INT 3 (0xCC) opcode, which the debuggers use to step through: https://github.com/copy/v86/discussions/653 https://github.com/copy/v86/discussions/653