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#ifdef ICD2_CPP
//convert linear pixel data to 2bpp planar tiledata
void ICD2::render(const uint32* source) {
memset(lcd.output, 0x00, 320 * sizeof(uint16));
for(unsigned y = 0; y < 8; y++) {
for(unsigned x = 0; x < 160; x++) {
unsigned pixel = *source++;
unsigned addr = y * 2 + (x / 8 * 16);
lcd.output[addr + 0] |= ((pixel & 1) >> 0) << (7 - (x & 7));
lcd.output[addr + 1] |= ((pixel & 2) >> 1) << (7 - (x & 7));
}
}
}
uint8 ICD2::read(unsigned addr) {
addr &= 0xffff;
//LY counter
if(addr == 0x6000) {
r6000_ly = GameBoy::ppu.status.ly;
r6000_row = lcd.row;
return r6000_ly;
}
//command ready port
if(addr == 0x6002) {
bool data = packetsize > 0;
if(data) {
for(unsigned i = 0; i < 16; i++) r7000[i] = packet[0][i];
packetsize--;
for(unsigned i = 0; i < packetsize; i++) packet[i] = packet[i + 1];
}
return data;
}
//ICD2 revision
if(addr == 0x600f) {
return 0x21;
}
//command port
if((addr & 0xfff0) == 0x7000) {
return r7000[addr & 15];
}
//VRAM port
if(addr == 0x7800) {
uint8 data = lcd.output[r7800];
r7800 = (r7800 + 1) % 320;
return data;
}
return 0x00;
}
void ICD2::write(unsigned addr, uint8 data) {
addr &= 0xffff;
//VRAM port
if(addr == 0x6001) {
r6001 = data;
r7800 = 0;
unsigned offset = (r6000_row - (4 - (r6001 - (r6000_ly & 3)))) & 3;
render(lcd.buffer + offset * 160 * 8);
return;
}
//control port
//d7: 0 = halt, 1 = reset
//d5,d4: 0 = 1-player, 1 = 2-player, 2 = 4-player, 3 = ???
//d1,d0: 0 = frequency divider (clock rate adjust)
if(addr == 0x6003) {
if((r6003 & 0x80) == 0x00 && (data & 0x80) == 0x80) {
reset();
}
switch(data & 3) {
case 0: frequency = cpu.frequency / 4; break; //fast (glitchy, even on real hardware)
case 1: frequency = cpu.frequency / 5; break; //normal
case 2: frequency = cpu.frequency / 7; break; //slow
case 3: frequency = cpu.frequency / 9; break; //very slow
}
r6003 = data;
return;
}
if(addr == 0x6004) { r6004 = data; return; } //joypad 1
if(addr == 0x6005) { r6005 = data; return; } //joypad 2
if(addr == 0x6006) { r6006 = data; return; } //joypad 3
if(addr == 0x6007) { r6007 = data; return; } //joypad 4
}
#endif
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