Turingon/8080-Emulator
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Still having I/O problems

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This commit is contained in:
Luxdragon 2024-01-14 11:00:05 +01:00
parent c304d49b24
commit 85bc469a9c
1 changed files with 44 additions and 43 deletions
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87
emulator_shell.c
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@ -397,6 +397,35 @@ void printState(State8080* state) {
state->e, state->h, state->l, state->sp);
}
uint8_t machineIn(State8080* state, uint8_t port) {
uint8_t a;
switch(port) {
case 3:
{
uint16_t v = (state->shift1<<8) | (state->shift0);
a = ((v >> (8-state->shift_offset)) & 0xff);
}
break;
}
return a;
}
uint8_t machineOut(State8080* state, uint8_t port, uint8_t value) {
switch(port) {
case 2:
{
state->shift_offset = value & 0x7;
} break;
case 4:
{
state->shift0 = state->shift1;
state->shift1 = value;
break;
}
}
}
int emulate8080(State8080* state) {
unsigned char *opcode = &(state->memory[state->pc]);
@ -696,7 +725,8 @@ int emulate8080(State8080* state) {
state->sp += 2;
break;
case 0xd3: // OUT byte
//printf("%c", opcode[1]);
uint8_t port = opcode[1];
machineOut(state, port, 0x00); // PROBLEM: We need to pass a value to machineOUT
state->pc++;
break;
case 0xd5: // PUSH D
@ -705,7 +735,8 @@ int emulate8080(State8080* state) {
state->sp -= 2;
break;
case 0xdb: // IN byte
//printf("%c", opcode[1]);
uint8_t port = opcode[1];
state->a = machineIn(state, port);
state->pc++;
break;
case 0xe1: // POP H
@ -781,9 +812,19 @@ int emulate8080(State8080* state) {
default: unknownInstruction(state); break;
}
printState(state);
}
void GenerateInterrupt(State8080* state, int interrupt_num)
{
//perform "PUSH PC"
Push(state, (state->pc & 0xFF00) >> 8, (state->pc & 0xff));
//Set the PC to the low memory vector.
//This is identical to an "RST interrupt_num" instruction.
state->pc = 8 * interrupt_num;
}
void read_Space_Invaders_ROM(State8080* state, const char* filename, int offset) {
//Works exclusively with the memory system of Space Invaders
FILE* file = fopen(filename, "rb");
@ -802,34 +843,6 @@ void read_Space_Invaders_ROM(State8080* state, const char* filename, int offset)
fclose(file);
}
uint8_t machineIn(State8080* state, uint8_t port) {
uint8_t a;
switch(port) {
case 3:
{
uint16_t v = (state->shift1<<8) | (state->shift0);
a = ((v >> (8-state->shift_offset)) & 0xff);
}
break;
}
return a;
}
uint8_t machineOut(State8080* state, uint8_t port, uint8_t value) {
uint8_t a;
switch(port) {
case 2:
{
state->shift_offset = value & 0x7;
} break;
case 4:
{
state->shift0 = state->shift1;
state->shift1 = value;
break;
}
}
}
int main (int argc, char *argv[]) {
gtk_init(&argc, &argv);
@ -861,18 +874,6 @@ int main (int argc, char *argv[]) {
char done = 0;
while (!done) {
uint8_t* opcode = &state->memory[state->pc];
printf("%d\t\t:", i);
if (*opcode == 0xdb) {
uint8_t port = opcode[1];
state->a = machineIn(state, port);
state->pc++;
} else if (*opcode == 0xd3) {
uint8_t port = opcode[1];
machineOut(state, port, 0x00);
state->pc++;
}
emulate8080(state);
i++;
sleep(0.00001);