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kalymos edited this page Mar 20, 2025 · 41 revisions

MCU currently supported.

• ATmega328/168 (Arduino Uno/Mini/Mini Pro)
• ATmega32u4 (Arduino Leonardo/Micro/Micro Pro)
• ATtiny25/45/85 (Not compatible with the BIOS patch)

The oversimplified way to do it

• Choosing your compilation options.
• Compilation.
• Configure fuses. 
    ◦ ATmega, H: DF, L: EE, E: FD
    ◦ ATtiny, H: DF, L: E2, E: FD
• Injecting the code into the target.
• Soldering the modchip according to the diagrams.

Find out if my console needs a BIOS patch

  • When a BIOS patch is needed: All Japanese consoles, and the European SCPH-102 console (PS One).
  • Consoles that don't need the BIOS patch: All American consoles, all fat European consoles, and all SCPH-xxx3 models.

You are required to use ISP injection in the following cases

  • When using ATtiny chips.
  • If your console requires a BIOS patch.

Personal recipe to make a good PSNee via ISP (complete tutorial for all possibilities)

Tutorial for injections via USB, only for Arduino without BIOS patch!

Pinout MCU & Arduino

Motherboard diagram

BIOS diagram

To determine your BIOS version, which is essential for old Japanese models, the BIOS dumper project works very well.

Other diagrams

PsNee modchip drawbacks

Due to the extensive coverage of different PS1 models, there is no universal compilation.

PsNee modchip advantages

The greatest strength of the PsNee modchip is that it is much more modern than PIC-based modchips and supports all PS1 models. Using AVR chips makes programming a PsNee chip easier, and many people may already have an Arduino that can be used as a PsNee modchip. Using more powerful processors allows the modchip to work with American, European, and Japanese PlayStation 1 consoles with a single chip. It can even patch the BIOS. Note that this BIOS patch does not work with ATtiny chips.

PsNee modchip source code

It supports the following microcontrollers:These chips fall into two categories, ATmega based chips, and ATtiny based chips. ATmega chips cost more, but allow for BIOS patching. ATtiny chips cost less. ATmega chips are also considerably larger in size, making them more difficult to fit into a system when compared to the ATtiny chips.

PAL and NTSC incompatibility with your TV

In North America, we have NTSC-U/C consoles and TVs, and in Japan, there are NTSC-J consoles and TVs. Meanwhile, Europe and some other regions use PAL consoles and TVs. On the PlayStation 1, the modchip unlocks the ability to output video for any region based on the game being played. However, not all TVs support all video formats. For example, if you insert a PAL game into your modded system and try to play it on an American TV, you might not get any video output.

To avoid this issue, I recommend buying a cheap composite-to-HDMI converter. These devices convert the unusual analog signal from a game of another region into a standard HDMI signal, ensuring compatibility with your TV.

Japanese consoles and video glitches with PAL games

Japanese consoles with specific clock signals can produce a bad video signal when playing PAL games. A known solution.

Things just for curiosity

Home

Personal recipe to make a good PSNee via ISP (complete tutorial for all possibilities)

Tutorial for injections via USB, only for ATmega without BIOS patch!

Pinout MUC & Arduino

Motherboard diagram

BIOS diagram

Other diagrams

BIOS Dumper 2.6

Why it doesn't work!

The rest is for curiosity

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