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5200 debugger

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I've made a debugger for the Atari 5200. You can view or modify memory, run programs, etc! I was about to add a disassembler, but I stopped before I went overboard Let me know if you need that and I can put it in.


This can be run on an emulator but is most effective on the real hardware.


Get it here: http://www.azstarnet.com/~jeffryj/5200bas.html


Have fun!



p.s. I'm still using a less effective keypad routine (it prevents repeats but sometimes misses characters you type). Anyone know how to write a good key repeat prevention routine? I know it's possible, take a look at the intro screen for 5200 Baseball. I appreciate any advice in this area.. Thanks!


[ 03-03-2002: Message edited by: calamari ]

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Just curious.. has anyone tried out DEBUG52? I'd be curious to hear any reactions.


I thought of one possible improvement. I could narrow the ROM down to a 16k version. Then it could be bundled with 16k games and used to investigate them on the 5200.


I should be able to add a few options to enable single step mode, breakpoints, or be able to run to a certain address (I'd have to experiment, but from what I understand you can trigger an interrupt when the CPU encounters a BRK instruction). This would bring functionality of the DEBUG52 program above what is seen in the current emulator monitors.


Would anyone be interested in seeing this implemented? Let me know.




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I was trying to think of where I could put the new functions for the possible 16k version and if I used Shift-0 that gives another slot.. then I'd also have Shift-7 thru Shift-9. So, without complicating things too much I can add 4 new functions!


I've been giving a bit of thought to how I can re-enter the debugger and then exit again without disturbing the game code. I can save registers, the IRQs and character set offsets and current IP on the stack.. as far as the flags go, I'm thinking maybe I can use a few branches at the very beginning to figure out which flags were set, then manually reconstruct those flag conditions before exiting again. If you know of an easier way to do the flags let me know


One thing I'm not too sure on how to do is to return back to the same place in the TV scan/display list as the program was in before. Any ideas on this? Maybe there is an ANTIC or GTIA register I could read for the value then put in a waiting loop when exiting?




[ 03-07-2002: Message edited by: calamari ]

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