gabonator

Reverse engineered firmware, injected extra code for simple image editor, running without PC

Should work with linux without any problem - cicoparser was initially developed on windows and does not use any libraries besides std, you can build it using gcc compiler... Host application is based on SDL2, so it should work really anywhere without any extra work

Good point. In the set of games (10 in total, release date up to 1991) I was porting I found only one that used this nasty technique. And it was just rewriting only single byte of code (something like rewriting nop instruction into return). So very simple case so far. Of course using cicoparser doesn't mean that you get working code without any manual work. You will always need to fix some issues by hand. Virtual memory does not solve anything in this case. Writing to EGA video ram means that you want to display some pixels. But the write operation goes through some extra logic which decides what to do with the byte being written (extra rotation, masking...) and by reading the same addrees you are not guaranteed to get the same value back. EGA control registers handle this process and you simply need to emulate this behaviour somehow.

If it was CPU emulator, it would update all the flags everytime performing any ALU operation (I have seen this approach in one source-to-source compiler). Actually, there is not much you can do: If the instruction stores SP into DS:123, it converts the instruction into simple assignment *((WORD*)&memory[ds*16+123]) = sp. All the ALU operations are directly calculated using the target instruction set, the flags register is updated only when necessary. Nor the memory is emulated, it directly accessess the memory buffer (in the video there are just extra range checks, even the *16 operation can be optimized replacing ds/es with memory pointers). Only thing that is emulated is the EGA adapter.

Cheap tool for recording and replaying radio signals

Hello guys,

few years ago I made an experiment where I translated the disassembled code of a game (Alley Cat, Star Goose) into C++ or Javascript. It was just a proof of concept and a lot of things needed to be fixed by hand. I sporadically returned to this experiment to improve the translation process. Now it has became quite powerful and standalone and this is a result (Star goose in swift):

https://youtu.be/IaZiQrUdR9s

Anyone interested in this topic? Anyone who would like to contribute to this project? It is in C++ and there are still a lot of things to be improved. Currently I am finetuning the conversion tool to port the Xenon2 game and I am looking to extend the compatibility to Borland C applications.

Gabriel