42
votes
Accepted
How were Western computer chips reverse-engineered in USSR?
Little is known about how these computers and chips were made, because their development was top secret in the Soviet Union.
As far as I know, Soviet Western-compatible ICs were made by copying ...
- 1,354
37
votes
How were Western computer chips reverse-engineered in USSR?
It seems to be pretty much accepted wisdom that the Soviets completely cloned the Western chips and did not simply develop reimplementations of the same instruction sets. Since at the time it was ...
- 1,780
24
votes
How were Western computer chips reverse-engineered in USSR?
This answer is written from memory, corrections may be made later if I remember/research more details. It starts with historical background to put things into perspective. This answer is specifically ...
- 341
21
votes
Accepted
What tools were used in late MS-DOS era for reverse engineering and patching binary executables?
As others have mentioned, “Program too big to fit in memory” means that DOS can’t find a large enough memory block to fit the amount of memory that your program’s header requests. This can be either ...
- 118k
19
votes
How were Western computer chips reverse-engineered in USSR?
You could reverse-engineer those early CPUs by grinding or etching away the top (plastic) layer of the chips down to the silicon die and examine the chip structures on an (optical) microscope.
(...
- 33k
18
votes
In the original Z80 layout, where are the "traps" located? And what are their effects?
Yes, there was at least one serious attempt to identify them, by Sergei Skorobogatov, who wrote an article about that: "Searching traps in Zilog Z80 CPU" back in 2014.
I don't know if I have ...
- 18.6k
18
votes
What information was "off limits" to IBM PC clone BIOS authors?
Apparently, US law allows analysis of an implementation as a base for a clean-room implementation, as long as the analysis and the implementation is done by separate teams that are only exchanging ...
- 33k
18
votes
Is there a common name for this 'switch' like 6800 assembly routine?
The term that comes to mind is "dispatch table". This is a table containing pointers to functions, one of which will be chosen based on an index that has been provided or gets calculated.
...
- 6,128
13
votes
Accepted
Did Digital Research clean-room MS-DOS?
Short Answer
Sort of. Digital Research had two teams, in different countries, that developed the product that became DR-DOS in two stages. The company that purchased DR-DOS only claimed in court that ...
- 8,549
13
votes
Accepted
How can I make the Microsoft C compiler for DOS emit a loop with an intermediate jump to continue?
It turns out that in MS C 5.1, in addition to all the /O... options there is one seemingly unrelated one that influences the optimizations for this compiler: /Zi. In the output of CL /help it is ...
- 857
12
votes
What tools were used in late MS-DOS era for reverse engineering and patching binary executables?
The simplest way to patch a .com file is DEBUG, which comes with any DOS installation.
DEBUG is partially usable for .exe files as well, but cannot reverse their relocation process, and so cannot ...
- 33k
12
votes
Accepted
Reverse engineering an RS-422 protocol with access to only one device?
I posted a comment on the reverse-engineering Q&A you linked before I realized it'd do better as an answer here.
The answerer there found that googling Accom and Axial from your photo turns up a ...
- 6,351
11
votes
Accepted
Dump process memory of Windows 3.1 control panel applet
Among the Borland Pascal 7 example programs, there is an OWL application called HeapSpy, which can inspect the list of memory blocks allocated by any running Windows module.
The demo is pretty ...
- 21.6k
11
votes
How are Amiga Kickstart Relocation Files (.RTB) created?
The job is non-trivial, but I don't think it would be hard for someone 'experienced in the art'. 256k or even 512k is not a lot of code, and the ROMs are highly structured with a well-defined ...
- 6,635
10
votes
How were Western computer chips reverse-engineered in USSR?
Computer development wasn't necessarily "top secret" as is commonly said about anything that has to do with the Soviet Union. The engineers there used the same methods as other companies in Taiwan. ...
- 202
9
votes
What is known about the internal workings of the Z80?
Z80 has been implemented in the Visual6502 way too. However looks like the site http://www.micrologo.net/z80x is no longer operational. It was Z80 die simulation in Javascript When I searched matching ...
- 7,228
9
votes
What tools were used in late MS-DOS era for reverse engineering and patching binary executables?
a bit off topic to your actual question but to make your game/exe whatever usable again:
Too much memory
common on MS-DOS for 32MByte and 64MByte (IIRC some versions use 32 some 64). The memory ...
- 7,228
8
votes
Accepted
How are Amiga Kickstart Relocation Files (.RTB) created?
I finally had to bite the bullet and do the exercise to create a .RTB of a ROM file which didn't have one: the old A1000 1.1 ROM (v31.34)
Bruce Abott answer is spot on on most parts, but devil is in ...
- 10.7k
8
votes
How can I extract game data from Nitemare 3D files?
The IMG.* files contains all textures and sprites in uncompressed/unencrypted state so its very easy to render, but there is no VGA palette there (nor in other files you posted). I found this:
...
- 7,228
8
votes
Accepted
How can I debug a Mac OS Classic application?
Back in the day, MacNosy was the go to disassembler tool to attack things like that. He also wrote a debugger. I can't speak to its status today. Apparently the web site still exists: https://www....
- 12.2k
8
votes
Is there a common name for this 'switch' like 6800 assembly routine?
Is there a common name for this 'switch' like 6800 assembly routine?
No. There is no specific name for exactly this technique. In fact, even generic names vary depending on whom to ask.
I do need to ...
- 213k
7
votes
What tools were used in late MS-DOS era for reverse engineering and patching binary executables?
The state of the art in assembly-level debugging of DOS programs is almost certainly SoftICE. I've never used it, but my understanding is that it was for a very long time the tool of choice of ...
- 12.8k
6
votes
How were Western computer chips reverse-engineered in USSR?
How were these chips made? Could they have possibly taken a Western chip and taken it apart somehow, to manually build a netlist, as was recently done to the 6502? Or was someone able to procure the ...
- 213k
6
votes
Accepted
Is otx (Object Tool Extended) still actively being maintained for reverse engineering legacy OS X binaries?
Technically, the most up to date modern fork of otx is being maintained by Zhi-Wei Cai on GitHub here. v1.7: Build 566 or a fresh clone of master should work on any modern OS X system.
But that's ...
- 9,432
6
votes
Reverse engineering an RS-422 protocol with access to only one device?
Options:
(1) Googling "Accom axial" finds various people who bought it, made Youtube reviews etc. If these are not you, contact them and see if they have details.
(2) As has been mentioned ...
- 26.1k
5
votes
Accepted
How can I extract game data from Nitemare 3D files?
Read and extract SND.DAT
Code is C# but is easy enough to understand and port to another language.
Basically there are 6 bytes entries that tells where is what in the file, some of them are dummy.
...
- 6,358
5
votes
What is known about the internal workings of the Z80?
The best I've seen is Goran Devic's implementation for an FPGA. He's taken the existing bits of Z-80 reverse engineering and filled in the missing pieces and connected them all together. Read ...
- 7,656
5
votes
Accepted
How big is one word in TG16 hardware?
The processor is a modified 6502 so one word is 8 bits. Many instructions are encoded as multiple words but for those the processor just fetches them in sequence when required.
I believe the graphics ...
- 36k
Only top scored, non community-wiki answers of a minimum length are eligible