New PS1 / Playstation / PSOne Modchip

Hi guys,

I made a new open source modchip for arduino, i've ported the PSOne version across to PIC but its missing the gate wire.

Code below for PU23 revision PS1.

//UberChip 4 wire stealth for PU23
// V2.00
// VajskiDs Consoles 2021
// Refer to Github for install diagrams @ GitHub - L10N37/tehUberChip_Another_PSX_Modchip: Another PSX modchip made in 2021 for arduino
// V1.1, Installed one today to ship off in this model, why wouldn't I? Spare arduinos on hand, doesn't interfere with the laser after boot and it takes 5 minutes to install.
// A tidy Mayumi installation can take an hour if you're a trying to be super neat.

// Gave it a quick test and it seems there was a slight oversight, like the PM41 version I have added genuine disc mode (start with lid open) as it was only working
// with burnt games
// and displaying Sony Computer Entertainment America with the SCEE string on the black Screen for NTSC US games, and the Sony Europe with SCEE string for copied PAL games
// and finally, Sony Computer Entertainment Inc. for Japanese games :slight_smile:
// V2.00 Used some lower level type code for reading and changing pin states and some general optimisation, added link wire needed for genuine imports
// at this stage, haven't been able to use software to produce this signal from an arduino.
// V2.10 Added support for Genuine and Genuine imports without a genuine mode. The ability to disable the chip still remains.
// The program used to make the calculations spits out a lot of broken code, used a pocket oscilliscope and uploaded a bunch of different settings and desired clock speeds until
// I had something on the scope that was almost a 1:1 match of the WFCK signal. This signal gets turned off once injections are complete.

#define DATA 12
#define databit 4
#define lidbit 0
int injectcounter = 0x00;
int bitdelay (3794); //delay between bits sent to drive controller (MS)
int stringdelay (160); //delay between string injections
char SCEE[] = "10011010100100111101001010111010010101110100S";
char SCEA[] = "10011010100100111101001010111010010111110100S";
char SCEI[] = "10011010100100111101001010111010010110110100";
//DEFAULT 'SCEE' INJECTION, CHANGE IN INJECT() TO SUIT YOUR REGION (x 3 references to character string)

void setup() {
//Set up the used pins
DATAIO = 0xFE; // 0B11111110; OPPOSITE OF TRISIO! set to ZERO for input, ONE for OUTPUT
DATAPORT = 0x00; // write all port b outputs low
void Genuine() { //Genuine disc mode (start PSX with lid open, then close)

void NewDisc() {
delay (1500);
while (bitRead (DATAPORT, lidbit) == 1);

void DriveLidStatus() {
TCCR1B = 0x18; // 0001 1000, Disable Timer Clock
bitClear (DATAIO, databit); // OPPOSITE OF TRISIO! set to ZERO for input, ONE for OUTPUT
injectcounter = 0;

if (bitRead (DATAPORT, lidbit) == 0) {
delay (1350) ;
else if (bitRead (DATAPORT, lidbit) == 1) {
delay (1350);
DriveLidStatus(); //forms a conditional if loop

void inject() {

// GATE WIRE SETUP***************************************
// RTM_TimerCalc 1.30,
// Timer-1 Mode_14_16Bit_Fast_TOP_is_ICR

TCCR1B = 0x18; // 0001 1000, Disable Timer Clock
TCCR1A = 0xA2; // 1010 0010

ICR1 = 2205-1;
OCR1A = (int) (ICR1 * 0.25);
OCR1B = (int) (ICR1 * 0.50);
TCCR1B |= 1; // Prescale=1, Enable Timer Clock

for (byte i = 0; i < sizeof(SCEE) - 1; i++)

  if (SCEE[i] == '0')
    bitWrite (DATAIO, databit, 1);  // OPPOSITE OF TRISIO! set to ZERO for input, ONE for OUTPUT
    bitClear (DATAPORT, databit);
    delayMicroseconds (bitdelay);
  else if (SCEE[i] == '1')
    bitClear (DATAIO, databit);     // OPPOSITE OF TRISIO! set to ZERO for input, ONE for OUTPUT
  else if (bitRead (DATAPORT, lidbit) == 1)
  else if (SCEE[i] == 'S')
    delay (stringdelay);

while (injectcounter < 86);

void loop()
if (injectcounter >= 86) {

if (bitRead (DATAPORT, lidbit) == 1) {
pinMode (DATA, INPUT);
Genuine(); // Disable uberchip
delay (4700); //start-up delay

1 Like

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.