kalymos.PsNee/PsNee.ino

// This PsNee version is meant for Arduino boards.
// 16Mhz and 8Mhz variants are supported. "Pro Micro" etc supported and recommended
// ATtinys should be able to do this as well; requires a bit of porting and testing

// PAL PM-41 support isn't implemented here yet. Use PsNee v6 for them.
// NTSC-U/J PM-41 are supported with PU22_MODE.

// By default, this code is multi-region. You can optimize it for your console, if you want to.
// Choose the correct inject_SCEX() for your console region.
// e = Europe / PAL
// a = North America / NTSC-U
// i = Japan / NTSC-J

// Use #define PU22_MODE for PU-22, PU-23, PM-41 mainboards.

#define PU22_MODE

//Pins
const int data = 8;         // Arduino pin 8, ATmega PB0 injects SCEX string. point 6 in old modchip Diagrams
const int SUBQ = 10;     // Arduino pin 10, ATmega PB2 "SUBQ" Mechacon pin 24 (PU-7 and early PU-8 Mechacons: pin 39)
const int SQCK = 11;    // Arduino pin 11, ATmega PB3 "SQCK" Mechacon pin 26 (PU-7 and early PU-8 Mechacons: pin 41)
//Timing
const int delay_between_bits = 4000; // 250 bits/s (microseconds)
const int delay_between_injections = 74; // 74 original, 72 in oldcrow (milliseconds)

// for PU-22 mode: specific delay times for the high bit injection. It depends on the MCU speed.
#if F_CPU == 16000000
const byte gate_high = 21;
const byte gate_low = 23;
#else
const byte gate_high = 20;
const byte gate_low = 20;
#endif

// SQCK (SUBQ clock) sampling timeout: All PSX will transmit 12 packets of 8 bit / 1 byte each, once CD reading is stable.
// If the pulses take too much time, we drop the byte and wait for a better chance. 1000 is a good value.
const int sampling_timeout = 1000;


//SCEE: 1 00110101 00, 1 00111101 00, 1 01011101 00, 1 01011101 00
//SCEA: 1 00110101 00, 1 00111101 00, 1 01011101 00, 1 01111101 00
//SCEI: 1 00110101 00, 1 00111101 00, 1 01011101 00, 1 01101101 00
const boolean SCEEData[44] = {1,0,0,1,1,0,1,0,1,0,0,1,0,0,1,1,1,1,0,1,0,0,1,0,1,0,1,1,1,0,1,0,0,1,0,1,0,1,1,1,0,1,0,0}; //SCEE
const boolean SCEAData[44] = {1,0,0,1,1,0,1,0,1,0,0,1,0,0,1,1,1,1,0,1,0,0,1,0,1,0,1,1,1,0,1,0,0,1,0,1,1,1,1,1,0,1,0,0}; //SCEA
const boolean SCEIData[44] = {1,0,0,1,1,0,1,0,1,0,0,1,0,0,1,1,1,1,0,1,0,0,1,0,1,0,1,1,1,0,1,0,0,1,0,1,1,0,1,1,0,1,0,0}; //SCEI

void inject_SCEX(char region)
{
  const boolean *SCEXData;
  switch (region){
    case 'e': SCEXData = SCEEData; break;
    case 'a': SCEXData = SCEAData; break;
    case 'i': SCEXData = SCEIData; break;
  }

  digitalWrite(LED_BUILTIN, HIGH); // this is Arduino Pin 13 / PB5

  for (byte bit_counter = 0; bit_counter < 44; bit_counter = bit_counter + 1)
  {
    if (*(SCEXData+bit_counter) == 0)
    {
      bitClear(PORTB,0); // pull data low
      delayMicroseconds(delay_between_bits);
    }
    else
    {
      unsigned long now = micros();
      do {
#ifdef PU22_MODE
        bitWrite(PORTB,0,1); // output high
        delayMicroseconds(gate_high);
        bitWrite(PORTB,0,0); // output low
        delayMicroseconds(gate_low);
#else
        bitSet(PORTB,0); // drag data pin high
#endif
      }
      while ((micros() - now) < delay_between_bits);
      //Serial.println((micros() - now));
    }
  }
  bitClear(PORTB,0); // pull data low
  delay(delay_between_injections);
 
  digitalWrite(LED_BUILTIN, LOW);
}

//--------------------------------------------------
//     Setup
//--------------------------------------------------
void setup()
{
  pinMode(data, INPUT); // Arduino pin 8, ATmega PB0
  pinMode(SUBQ, INPUT); // spi data in Arduino pin 10, ATmega PB2
  pinMode(SQCK, INPUT); // spi clock Arduino pin 11, ATmega PB3
  pinMode(LED_BUILTIN, OUTPUT); // Blink on injection / debug.
  Serial.begin (1000000);
  Serial.println("Start ");
 
  // Power saving
  // Disable the ADC by setting the ADEN bit (bit 7)  of the
  // ADCSRA register to zero.
  ADCSRA = ADCSRA & B01111111;
  // Disable the analog comparator by setting the ACD bit
  // (bit 7) of the ACSR register to one.
  ACSR = B10000000;
  // Disable digital input buffers on all analog input pins
  // by setting bits 0-5 of the DIDR0 register to one.
  DIDR0 = DIDR0 | B00111111;
}

void loop()
{
  static unsigned int num_resets = 0; // debug / testing
  static byte scbuf [12] = { 0 }; // We will be capturing PSX "SUBQ" packets, there are 12 bytes per valid read.
  static byte scpos = 0;          // scbuf position

  static unsigned int timeout_clock_counter = 0;
  static byte bitbuf = 0;         // SUBQ bit storage
  static bool sample = 0;

  // Capture 8 bits per loop run.
  // unstable clock, bootup, reset and disc changes are ignored
  noInterrupts(); // start critical section

// yes, a goto jump label. This is to avoid a return out of critical code with interrupts disabled.
// It prevents bad behaviour, for example running the Arduino Serial Event routine without interrupts.
// Using a function makes shared variables messier.
// SUBQ sampling is essential for the rest of the functionality. It is okay for this to take as long as it does.
start:

  for (byte bitpos = 0; bitpos<8; bitpos++) {
    do {
      // nothing, reset on timeout
      timeout_clock_counter++;
      if (timeout_clock_counter > sampling_timeout){
        scpos = 0;  // reset SUBQ packet stream
        timeout_clock_counter = 0;
        num_resets++;
        bitpos = 0;
        goto start;
      }
    }
    while (bitRead(PINB, 3) == 1); // wait for clock to go low
   
#if F_CPU == 16000000 // wait a few cpu cycles > better readings in tests
    __asm__("nop\n\t"); __asm__("nop\n\t"); __asm__("nop\n\t");
#endif

    // sample the bit.
    sample = bitRead(PINB, 2);
    bitbuf |= sample << bitpos;

    do {
      // nothing
    } while ((bitRead(PINB, 3)) == 0); // Note: Even if sampling is bad, it will not get stuck here. There will be clock pulses eventually.

    timeout_clock_counter = 0; // This bit came through fine.
  }
 
  scbuf[scpos] = bitbuf;
  scpos++;
  bitbuf = 0;

  if (scpos < 12){
    goto start;
  }

  interrupts(); // end critical section
 
  // logging.
  if (!(scbuf[0] == 0 && scbuf[1] == 0 && scbuf[2] == 0 && scbuf[3] == 0)){ // a bad sector read is all 0 except for the CRC fields. Don't log it.
    for (int i = 0; i<12;i++) {
      Serial.print(scbuf[i], HEX);
      Serial.print(" ");
    }
    Serial.print(" resets:  ");
    Serial.println(num_resets);
  }

  num_resets = 0;
  scpos = 0;
 
  // check if this is the wobble area
  // 3 bytes would be enough to recognize it. The extra checks just ensure this isn't a garbage reading.
  if ( (scbuf[0] == 0x41 &&  scbuf[1] == 0x00 &&  scbuf[6] == 0x00) && // 0x41 = psx game, beginning of the disc, sanity check
    ((scbuf[2] == 0xA0 || scbuf[2] == 0xA1 || scbuf[2] == 0xA2) ||
    (scbuf[2] > 0x00 && scbuf[2] <= 0x99)) ){ // lead in / wobble area
   
    Serial.println("INJECT!");

    pinMode(data, OUTPUT); // prepare for SCEX injection

    bitClear(PORTB,0); // pull data low
   
    // HC-05 is waiting for a bit of silence (pin Low) before it begins decoding.
     // minimum 66ms required on SCPH-7000
     // minimum 79ms required on SCPH-7502 // wrong! got to keep the NRZ signal in mind for PU22+ !
     delay(82);
   
    for (int loop_counter = 0; loop_counter < 2; loop_counter++)
    {
       inject_SCEX('e'); // e = SCEE, a = SCEA, i = SCEI
       inject_SCEX('a'); // injects all 3 regions by default
       inject_SCEX('i'); // makes it easier for people to get working
    }

    pinMode(data, INPUT); // high-z the data line, we're done
  }
// keep catching SUBQ packets forever
}

// Old readme!

//UPDATED AT MAY 14 2016, CODED BY THE FRIENDLY FRIETMAN :-)

//PsNee, an open source stealth modchip for the Sony Playstation 1, usable on
//all platforms supported by Arduino, preferably ATTiny. Finally something modern!


//--------------------------------------------------
//                    TL;DR
//--------------------------------------------------
//Look for the "Arduino selection!" section and verify the target platform. Hook up your target device and hit Upload!
//BEWARE: when using ATTiny45, make sure the proper device is selected (Extra=>Board=>ATTiny45 (internal 8MHz clock))
//and the proper fuses are burnt (use Extra=>Burn bootloader for this), otherwise PsNee will malfunction. A tutorial on
//uploading Arduino code via an Arduino Uno to an ATTiny device: http://highlowtech.org/?p=1695
//Look at the pinout for your device and hook PsNee up to the points on your Playstation.

//The modchip injects after about 1500ms the text strings SCEE SCEA SCEI on the motherboard point and stops
//with this after about 25 seconds. Because all the possible valid region options are outputted on the
//motherboard the Playstation gets a bit confused and simply accepts the inserted disc as authentic; after all,
//one of the codes was the same as that of the Playstation hardware...

//--------------------------------------------------
//               New in this version!
//--------------------------------------------------
//A lot!
// - The PAL SCPH-102 NTSC BIOS-patch works flawlessly! For speed reasons this is implemented in bare
//   AVR C. It is functionally identical to the OneChip modchip, this modchip firmware was disassembled,
//   documented (available on request, but written in Dutch...) and analyzed with a logic analyzer to
//   make sure PsNee works just as well.
// - The code now is segmented in functions which make the program a lot more maintable and readable
// - Timing is perfected, all discs (both backups and originals of PAL and NTSC games) now work in the
//   PAL SCPH-102 test machine
// - It was found out that the gate signal doesn't havbe to be hooked up to a PAL SCPH-102 Playstation
//   to circumvent the copy protection. This is not tested on other Playstation models so the signal still
//   is available
// - The /xlat signal is no longer required to time the PAL SCPH-102 NTSC BIOS-patch
// - Only AVR PORTB is used for compatibility reasons (almost all the AVR chips available have PORTB)