EPR-15112 information

void main(){
	setStackPointer(0xA000);
	disableInterrupts();
	setInterruptMode(0);
	setupComm();
}

void int5(){
	byte A;

	A = 32;
	do {
		A--;
	} while(A > 0);
	memw(0x8000, memr(0x8000)--);
	enableInterrupts();
}

void int7(){
	byte A;

	A = ior(0x08);
	A = ior(0x0F);
	A = ior(0x0C):
	if(A & 1){
		A ^= A;
		iow(0x0F, A);
	}
	enableInterrupts();
}

void setupComm(){
	byte A;

	resetComm();
	zeroInternalMemory();
	testVInt120();

	resetComm();

	A = memr(0xC001);
	A--;
	if (A == 0){
		// Master
		setupRingMaster();
		copyAndConfigDma();
		waitVInt();
		syncCommon150();
		loopMaster();
	} else {
		// Slave & Relay
		setupRingSlaveRelay();
		copyAndConfigDma();
		readCommon150();
		loopSlaveRelay();
	}
}

void syncCommon150(){
	byte A;

	A = 0x96; // 150
	memw(0x8001, A);

	do {
		syncCommon();
		A = memr(0x8001);
		A--;
		memw(0x8001, A);
	} while (A > 0);
}

void zeroMemory(int HL, int BC){
	int DE;

	memw(HL, 0x00);

	DE = HL;
	DE++;
	BC--;

	while (BC > 0){
		memw(DE, memr(HL));
		DE++;
		HL++;
		BC--;
	}
}

void resetComm(){
	memw(0xC000, 5);

	resetDlc();
	resetDma();

	iow(0x60, 0);
	iow(0x40, 0);

	memw(0x800E, 0);
	memw(0x8006, 0);
	memw(0x8007, 0);
	memw(0x8003, 2);

	// 0 = relay, 1 = master, 2 = slave
	byte a = memr(0xC001);

	if (a == 0) {
		// relay
		memw(0x8007, 1);
		memw(0xC004, 1);
		return;
	}

	a--;
	if (a == 0) {
		// master
		return;
	} else {
		// slave
		memw(0x8006, 1);
		return;
	}
}

void testVInt120(){
	byte A = 120;
	memw(0x8001, A);
	
	do {
		waitVInt();
		A = memr(0x8001)
		A--
		memw(0x8001, A);
	} while(A > 0);
}

void setupRegisters(int HL, int B){
	byte C;
	do {
		C = memr(HL);
		HL++;
		iow(C, memr(HL));
		B--;
	} while (B > 0);
}

void zeroInternalMemory(){
	zeroMemory(0x8000, 0x1FF0);
}

void resetDlc(){
	ior(0x0C);
	iow(0x0C, 0x60);

	for(b=0x10;b>0;b--){
		ior(0x08);
		ior(0x0F);
	}

	setupRegisters(0x011E, 0x0C);
}

void resetDma(){
	setupRegisters(0x013E, 0x03);
}

void waitVInt(){
	byte a = 2;
	iow(0x40, a); // enable vint

	a ^= a;       // 2 ^ 2 = 0?
	memw(0x8000, a);
	enableIrqs();

	hl = 0x8000;
	while (memr(hl) - a == 0){}

	memw(hl, a);
}

void setupRingMaster(){
	byte A;
	byte R;

	ior(0x08);

	setupRegisters(0x011E, 0x10);

	iow(0x40, 0x02); // enable vint

	A = 0x4B;
	do {
		R = sendByteBeforeVInt(A);
	} while(R != A);

	wait255();

	A = 0x61;
	do {
		R = sendByteBeforeVInt(A);
	} while(R != A);

	wait255();

	A = 0x7A;
	do {
		R = sendByteBeforeVInt(A);
	} while(R != A);

	waitVInt;
	wait255();

	do {
		R = sendByteBeforeVInt(A);
	} while(R != A);

	waitVInt;
	wait255();

	A = 0x01;
	memw(0x8009) = A;
	memw(0xC002) = A; // this is the node id

	R = sendByteBeforeVInt(A);
	memw(0x8008) = R;
	memw(0xC003) = R; // this is the node count

	waitVInt;
	wait255();

	A = memr(0x8008);
	R = sendByteBeforeVInt(A);

	flushRXTX();

	disableRXTX();

	validateRingSize();
}

void validateRingSize(){
	byte A;

	A = memr(0x8008);
	if (A < 9){
		return;
	} else {
		memw(0xC000, A);
		disableInterrupts();
		System.exit(A);
	}
}

void disableRXTX(){
	iow(0x17, 0xFF);
	iow(0x0A, 0x03);
	iow(0x0D, 0x08);
}

void enableRXTX(){
	iow(0x0A, 0x80);
	iow(0x0D, 0x80);
}

void flushRX(){
	byte A;

	flushRXTX();

	do {
		ior(0x09);
		A = ior(0x08);
		A &= 0x01;
		if (A == 0) {
			break;
		}
		A = ior(0x0F);
	}
}

void wait255(){
	byte a = 0; ' a ^= a
	do (){
		a--;
	} while (a > 0);
}

void wait20(){
	byte a = 0x14;
	do (){
		a--;
	} while (a > 0);
}

void wait40(){
	byte a = 0x28;
	do (){
		a--;
	} while (a > 0);
}

void setupRegisters_HLB(){
	setupRegisters_HLB(0x8040);
}

void setupRegisters_HLB(int HL){
	setupRegisters_HLB(HL, 0x13);
}

void setupRegisters_HLB(int HL, int B){
	do {
		byte C = memr(HL);
		HL++;
		iow(C, memr(HL));
		B--;
	} while (B > 0);
}