PS1USB v1.0 by OrionSoft [2024]
https://orionsoft.games/

PS1USB is a development cartridge for the Playstation 1 allowing data transfer between your computer and your Playstation 1 over USB.
This cartridge must be used with a USB mini-B cable and the provided "ps1transfer" tool available for Windows 32/64bits and Linux 64bits.

The ps1transfer folder contains the source code of the tool running on your computer and used to transfer data over USB to the PS1USB cartridge.
Linux coders must install libftdi1-dev (Under Debian: sudo apt-get install libftdi1-dev)
I'm using CodeBlocks as a development environment, so I provide the corresponding ".cbp" project files for Linux and Windows.

The ps1usb folder contains the source code for the PS1USB cartridge firmware.
The firmware runs from RAM at address 0x801F6000.
It is copied at boot from the cartridge ROM to RAM using https://github.com/JonathanDotCel/RomProd (see the "rom" folder)
As the "LoadImage" function doesn't seems to work when loading data from the ROM space, and to save RAM space for user upload,
I made a small file system for storing the TIM images in the ROM at address 0x1F010000.
The the firmware boot, these TIM images are copied from ROM to RAM at address 0x80010000 then transfered in VRAM.
At boot, before trashing the VRAM, I copy the entire VRAM content at the address 0x80020000 to 0x8011FFFF so that the ps1transfer tool can download VRAM data from this address using the "-v" command.

The exception handler crash screen is taken from https://gist.github.com/impiaaa/2c97419435cad2f40fe8a495d696ec52
and was modified to use a new 8x8 font (instead of the bios font), and print the CPU registers list and the crash Cause in plain ascii text.

The transfer protocol is in the file "usb.h"
I'm not an expert in this domain so, someone might code a faster protocol, if so, then feel free to send me patches, that's why the code is open source.

If you want to add new features to this firmware, you can compile it at address 0x801D0000 and transfer it like a regular PS-X EXE.
If you want me to add your new features to the production firmware/update, you can send me the patch to: orionsoft@free.fr

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.

OrionSoft / June 2024