Questions tagged [debugging]

The process of discovering and diagnosing bugs in software. Use [bugs] to ask about specific defects in well-known software that are already known and (presumably) understood.

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Do people fix software bugs in old arcade games?

Do people fix software bugs in old coin-op arcade games? Here is one list of arcade game bugs. Presumably the ROM images that run on emulators like MAME allow reverse compilation. This would allow ...
user2023370's user avatar
16 votes
2 answers
3k views

What contemporary hardware was available for the development of Atari 2600 (or other 2nd gen) games?

The Atari 2600, along with others like the Odyssey 2 or Intellivision, were among the first programmable home game consoles. They existed alongside personal computers like the Apple II and Commodore ...
David's user avatar
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2 votes
0 answers
143 views

Using 386SWAT to trace a program through a transition from real mode into protected mode

The 386SWAT debugger seems to be able to continue tracing a real-mode (not V86) program that goes into protected mode, but I don't quite understand how to configure 386SWAT, and I can't find any ...
MRICHARD's user avatar
5 votes
0 answers
218 views

Where can I find a schematic of the AT&T KBD 301?

Where can I find a schematic of the AT&T KBD 301? I have an old AT&T 6300 (AT&T's rebrand of the Olivetti M24) but the keyboard (AT&T KBD 301) is not working. Many of the keys do work ...
user4574's user avatar
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8 votes
3 answers
723 views

History of static analysis tools for defect identification

As part of an article I'm writing, I wanted to give a sense of how long static analysis tools have been with us. There was no mention of them in my copy of The Mythical Man-month (1982 edition). This ...
kdgregory's user avatar
  • 183
13 votes
1 answer
2k views

Did x86 CPU vendors like Intel, NEC, AMD, and Cyrix provide their own debugger for DOS with better CPU support and was it free?

MS-DOS's debugger DEBUG.EXE did only support the assembly/disassembly of 8086 opcodes. DR-DOS's debugger SID86.EXE, SID.EXE and Novel's debugger DEBUG.EXE did support 80286 opcodes and more, but no ...
Coder's user avatar
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12 votes
1 answer
370 views

What is the difference between the different versions of the SID or SID86 debugger for the x86 PC that was shipped with the different DR-DOS versions?

I did a little research about Digital Research's 8086 Symbolic Instruction Debugger. Short name SID86.EXE and SID.EXE in later versions. But I couldn't find some sort of version history? I would ...
Coder's user avatar
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2 votes
1 answer
367 views

Obtaining a CPU execution trace on a Commodore 64 [closed]

I need to collect the execution trace of all instructions executed by the 6502 on a C64. I tried C64 Debugger, but I couldn't find any option for this. Is it possible to obtain with C64 Debugger? Are ...
Digerkam's user avatar
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17 votes
1 answer
1k views

What did memory dumps look like on 36-bit machines like PDP-10s?

I spend a lot of time looking at hex dumps of memory, which have a format that should be familiar to most: 00010000 00 FF 48 65 6c 6c 6f 20-77 6f 72 6c 64 21 00 00 ..Hello world!.. But on 36-bit ...
John Källén's user avatar
10 votes
2 answers
2k views

Is there a standard interface for connecting debuggers to emulators?

Does any emulator have an interface, let's say with sockets, to which an arbitrary application can connect and get data so as to implement a debugger or monitor, etc? I know you could achieve this by ...
Petruza's user avatar
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6 votes
1 answer
442 views

How can I install debug VXDs from the Windows 98 DDK?

The core OS debug VXDs are provided in the DDK as separate VXDs, as opposed to being packed into a single VMM32.VXD file. Furthermore the readme file with the DDK indicates that copying all the ...
user1628056's user avatar
193 votes
1 answer
56k views

Why does trying to break into the NT 3.1 kernel reboot my 486DX4 machine?

I installed Windows NT 3.1 on a Compaq ProSignia 3080 system, because of several reasons: I know that this machine was running Windows NT 3.1 when it was in productive use. And I think this machine ...
Michael Karcher's user avatar
26 votes
2 answers
7k views

How did the "Programmer's Switch" work on early Macintosh Computers?

The early Apple Macintosh computers (original Mac, Mac 512K, Mac Plus) all came with a "Programmer's Switch" installed on the side. I believe this persisted for a long time, with the switch ...
Brian H's user avatar
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6 votes
1 answer
419 views

Dump process memory of Windows 3.1 control panel applet

I'm trying to work out how a Control Panel applet on Windows 3.1, which interacts with some host-specific hardware, works and as part of this I'd like to dump the contents of memory which the process ...
David Gardner's user avatar
3 votes
0 answers
201 views

Use MAME debugger for Amiga software [closed]

I have used the MAME debugger a lot with arcade machine emus. Now I would like to use it to help debug a game I build for Amiga. Having set up A500 emulation in MAME by adding the roms, I can start it,...
Blindleistung's user avatar
11 votes
1 answer
749 views

How did ZX81 assembly debuggers implement breakpoints?

What techniques were used for implementing breakpoints on the ZX81? Traditionally for the 8086 int 3h is used, for the 8080 on CP/M with DDT RST 7 as single byte replacements, 6502 has the BRK ...
PeterI's user avatar
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29 votes
9 answers
7k views

What was the first mainstream advanced debugger?

What was the first mainstream development toolchain that provided advanced debugging facilities? By "mainstream" I mean something that was available on home computers, not mainframes or super-...
dim's user avatar
  • 1,608
14 votes
2 answers
1k views

Can I trigger the Amiga ROM debugger from the boot prompt?

Suppose I have an Amiga computer without any working boot disks. Is it possible to trigger the built-in ROM monitor (RomWack or SAD, see https://theamigamuseum.com/amiga-kickstart-workbench-os/guru-...
user3570736's user avatar
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7 votes
3 answers
1k views

How can I debug a Mac OS Classic application?

I have a Mac OS Classic application (a game) that I want to "debug". It has data files in a unique format than I am attempting to reverse-engineer. I've made some progress with a hex editor, but ...
Greg Kennedy's user avatar
7 votes
0 answers
400 views

How was the Intel 80486 debugged? [closed]

How was the Intel 80486 (from 1989) debugged? I'm assuming it was written in some HDL language, like Verilog. However, how was testing and debugging of the CPU carried out? Were there several steps ...
AlphaCentauri's user avatar
5 votes
3 answers
564 views

Why is memory below the stack pointer constantly being overwritten under a debug session?

When I run a debug session using FreeDOS and DEBUG.EXE, I get a session like the following. I've added a description of what I saw as annotation on the image. Each step, I've printed out the stack ...
Byron Katz's user avatar
2 votes
1 answer
373 views

Is it possible to use the BRK instruction when ROM is banked out?

I used to use the BRK instruction when debugging on the C64. However, when I bank out ROM with... lda #$35 // Bank out kernal and basic sta $01 // $e000-$ffff ...the BRK instruction (...
Nurpax's user avatar
  • 495
15 votes
11 answers
4k views

Commercially available computer with single-step feature?

Was there ever a commercially available hobbyist/teaching computer with the ability to single-step the processor? Maybe a Z80-based machine?
Kenneth Sizer's user avatar
9 votes
3 answers
988 views

What is the first computer architecture that knew code from data?

The CPU being able to tell code and data apart to prevent inadvertent or malicious execution of data as instructions by trapping (even if the bit pattern of the data can be interpreted as a valid ...
Leo B.'s user avatar
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12 votes
1 answer
498 views

Does a CDC 1604 emulator exist with a functional FORTRAN compiler?

The first FORTRAN compiler for the Soviet BESM-6 mainframe was written by means of manually retargeting the assembly code of the CDC 1604 FORTRAN compiler donated by CERN to JINR. As a result is it ...
Leo B.'s user avatar
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9 votes
1 answer
390 views

Remote Debugging on the Atari ST

Were there ever any remote debugging tools for the Atari ST line of machines? When developing games in full screen modes, switching away to a debugger seems quite cumbersome if you need to remember ...
Matt Lacey's user avatar
  • 2,212
18 votes
9 answers
3k views

How were bugs reported for compilers that were shipped on floppy disks?

Take the Microsoft C 1.0 compiler for example. It shipped on multiple 5.25" 360K disks, and when it ran on machines without internal hard disk, so users had to switch floppies between the editor, ...
JAL's user avatar
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25 votes
8 answers
3k views

How did debugging software run without memory protection?

Debuggers are carefully written programs that peek and poke other programs while they run. In retrocomputers, programs could use any part of the memory they could access. So how did debuggers insert ...
wizzwizz4's user avatar
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