The Mayumi v2.1 was a modchip that was recommended for all fat PlayStation 1 board models. The code runs on a more expensive PIC16F84 chip.

This is actually a potentially desirable chip for the older PU-7 and PU-8 boards that don’t work with the Mayumi v4, and don’t always work very well with the MM3. The biggest drawback is the higher cost of the chip, and the additional wires that need to be soldered.

This chip has several modes that can be changed by pressing reset for three seconds or more. It defaults to having the modchip enabled. An LED can be hooked up to the chip to indicate which mode is active.

Mode toggle flow for PU-7 boards:

1. PU-7 strongest mode (default) (supports all anti-modchip games)
2. Old modchip mode
3. Modchip disabled

Mode toggle flow for PU-8, PU-18, and PU-20 boards:

1. Mayumi v1.0 mode (default) (supports many anti-modchip games)
2. Mayumi v0.9 mode (supports many anti-modchip games)
3. Old modchip mode
4. Modchip disabled

Mode toggle flow for PU-22, and PU-23 boards:

1. PU-22/PU-23 strongest mode (default) (supports all anti-modchip games)
2. Mayumi v0.9 mode (supports many anti-modchip games)
3. Old modchip mode
4. Modchip disabled

The chip fuses need to be set as WDT_OFF, XT_OSC, and PWRTE_ON.

Hex code:

• Coming soon.

LED diagram

PU-7 board diagram

PU-8 board diagram

PU-18 board diagram

PU-20 board diagram

PU-22 board diagram

PU-23 board diagram

PM-41 board diagram