I don't mean hooks in an emulator for injection of assets from outside the game; instead I mean changing a few lines of code (if it is that simple) in a PS1 emulator so it has 64 (or 128, or what have you) MB of RAM instead of 2 MB. Ditto with "improving" the other specs so long as the limitations of those specs aren't used by a game for (I guess) timing, or something important. Maybe more VRAM, a larger texture cache, support for resolutions higher than 640x480, more RAM for the SPU, disc images larger than 660 MB, support for Neil Corlett's ECMs...
I agree, it makes no sense to write a new PS1 emulator from scratch. If that's what I came across as asking about, I apologize. Instead, I'm wondering if and how one could make minimal modifications to existing PS1 emulators to capture low-hanging fruit IRT improved capabilities or performance, with no or minimal unwanted side effects.
If someone ever makes a handheld FPGA emulation device, such improvements to the base systems would be wonderful to have.
As for the PSP, it's instruction set is a superset of the PS1. If you have a disassembly which can be reassembled 1 for 1 to make the PS1 executable files, wouldn't it just be a matter of changing I guess the BIOS-specific code/calls to match that of the PSP, then building a disc image which would work on a modded PSP or PSP emulator (and NOT by using the PS1 backwards compatability of those systems)?
I vaguely remember a project that did something similar with I think PowerPC hardware and either NES or SNES software.
Unrelated, but if you want to avoid dealing with proprietary PS1 bios files (Yes, I do know you meant the PSP bios), this team is/was developing an open source PS1 bios:https://github.com/grumpycoders/pcsx-redux/tree/main/src/mips/openbios
...as part of a project to improve and modernize PCSX:https://github.com/grumpycoders/pcsx-redux
This is yet another fork of the Playstation Emulator, PCSX. While the work here is very much in progress, the goal is roughly the following:
- Bring the codebase to more up to date code standards.
- Get rid of the plugin system and create a single monolithic codebase that handles all aspects of the playstation emulation.
- Write everything on top of SDL/OpenGL3+/ImGui for portability and readability.
- Improve the debugging experience.
- Improve the rendering experience.