215 lines
6.9 KiB
C
215 lines
6.9 KiB
C
/**
|
|
* PAT80 Emulator
|
|
*
|
|
* Emulates a PAT80.
|
|
*/
|
|
|
|
#include <Z/constants/pointer.h> /* Z_NULL */
|
|
#include <Z80.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <ncurses.h>
|
|
|
|
#define ROM_SIZE 0x8000 /* 32 KiB */
|
|
#define MEMORY_SIZE 0xFFFF /* 64 KiB */
|
|
|
|
typedef struct {
|
|
void* context;
|
|
zuint8 (* read)(void *context);
|
|
void (* write)(void *context, zuint8 value);
|
|
} Device;
|
|
|
|
typedef struct {
|
|
zusize cycles;
|
|
zuint8 memory[65536];
|
|
Z80 cpu;
|
|
} Machine;
|
|
|
|
|
|
static zuint8 machine_cpu_read(Machine *self, zuint16 address) {
|
|
return address < MEMORY_SIZE ? self->memory[address] : 0xFF;
|
|
}
|
|
|
|
|
|
static void machine_cpu_write(Machine *self, zuint16 address, zuint8 value) {
|
|
if (address >= ROM_SIZE && address < MEMORY_SIZE)
|
|
self->memory[address] = value;
|
|
}
|
|
|
|
|
|
static zuint8 machine_cpu_in(Machine *self, zuint16 port) {
|
|
// Pat80 has 8 devices, decoded based on the 3 most significant IO addr bits.
|
|
// Note the Z80 has 16 bit address bus, but only the first 8 are used as IO addr,
|
|
// so the 3 most significant IO addr bits in this case are A7, A6, A5. The bits
|
|
// A4-A0 may be used by the single device, at its own discretion.
|
|
zuint16 bitmask = 7; // 0000000000000111
|
|
int decoded = port & bitmask;
|
|
if (decoded <= 0x1F) {
|
|
// Port 0 (0x00 to 0x1F): terminal
|
|
// Read char from stin
|
|
return getch();
|
|
}
|
|
if (decoded <= 0x3F) {
|
|
// Port 1 (0x20 to 0x3F): sound card (sn76489)
|
|
printw("\nsound_cmd[IN]: Not supported!\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x5F) {
|
|
// Port 2 (0x40 to 0x5F)
|
|
printw("IO_ERROR_IN: No device at port 2\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x7F) {
|
|
// Port 3 (0x60 to 0x7F)
|
|
printw("IO_ERROR_IN: No device at port 3\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x9F) {
|
|
// Port 4 (0x80 to 0x9F)
|
|
printw("IO_ERROR_IN: No device at port 4\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x5F) {
|
|
// Port 5 (0xA0 to 0xBF)
|
|
printw("IO_ERROR_IN: No device at port 5\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x5F) {
|
|
// Port 6 (0xC0 to 0xDF)
|
|
printw("IO_ERROR_IN: No device at port 6\n");
|
|
return 0x00;
|
|
}
|
|
if (decoded <= 0x5F) {
|
|
// Port 7 (0xE0 to 0xFF)
|
|
printw("IO_ERROR_IN: No device at port 7\n");
|
|
} else {
|
|
printw("IO_ERROR_IN: Invalid port address: %#04x\n", port);
|
|
}
|
|
}
|
|
|
|
|
|
static void machine_cpu_out(Machine *self, zuint16 port, zuint8 value) {
|
|
// Pat80 has 8 devices, decoded based on the 3 most significant IO addr bits.
|
|
// Note the Z80 has 16 bit address bus, but only the first 8 are used as IO addr,
|
|
// so the 3 most significant IO addr bits in this case are A7, A6, A5. The bits
|
|
// A4-A0 may be used by the single device, at its own discretion.
|
|
zuint16 bitmask = 0xE0; // 0000000011100000
|
|
int decoded = port & bitmask;
|
|
if (decoded <= 0x1F) {
|
|
// Port 0 (0x00 to 0x1F): terminal
|
|
attron(A_BOLD);
|
|
printw("%c", value);
|
|
attroff(A_BOLD);
|
|
} else if (decoded <= 0x3F) {
|
|
// Port 1 (0x20 to 0x3F): sound card (sn76489)
|
|
printw("\nsound_cmd[%#04x]\n", value);
|
|
} else if (decoded <= 0x5F) {
|
|
// Port 2 (0x40 to 0x5F)
|
|
printw("IO_ERROR_OUT: No device at port 2\n");
|
|
} else if (decoded <= 0x7F) {
|
|
// Port 3 (0x60 to 0x7F)
|
|
printw("IO_ERROR_OUT: No device at port 3\n");
|
|
} else if (decoded <= 0x9F) {
|
|
// Port 4 (0x80 to 0x9F)
|
|
printw("IO_ERROR_OUT: No device at port 4\n");
|
|
} else if (decoded <= 0x5F) {
|
|
// Port 5 (0xA0 to 0xBF)
|
|
printw("IO_ERROR_OUT: No device at port 5\n");
|
|
} else if (decoded <= 0x5F) {
|
|
// Port 6 (0xC0 to 0xDF)
|
|
printw("IO_ERROR_OUT: No device at port 6\n");
|
|
} else if (decoded <= 0x5F) {
|
|
// Port 7 (0xE0 to 0xFF)
|
|
printw("IO_ERROR_OUT: No device at port 7\n");
|
|
} else {
|
|
printw("IO_ERROR_OUT: Invalid port address: %#04x\n", port);
|
|
}
|
|
}
|
|
|
|
|
|
void machine_initialize(Machine *self) {
|
|
self->cpu.context = self;
|
|
self->cpu.fetch_opcode =
|
|
self->cpu.fetch =
|
|
self->cpu.nop =
|
|
self->cpu.read = (Z80Read )machine_cpu_read;
|
|
self->cpu.write = (Z80Write)machine_cpu_write;
|
|
self->cpu.in = (Z80Read )machine_cpu_in;
|
|
self->cpu.out = (Z80Write)machine_cpu_out;
|
|
self->cpu.halt = Z_NULL;
|
|
self->cpu.nmia = Z_NULL;
|
|
self->cpu.inta = Z_NULL;
|
|
self->cpu.int_fetch = Z_NULL;
|
|
self->cpu.ld_i_a = Z_NULL;
|
|
self->cpu.ld_r_a = Z_NULL;
|
|
self->cpu.reti = Z_NULL;
|
|
self->cpu.retn = Z_NULL;
|
|
self->cpu.hook = Z_NULL;
|
|
self->cpu.illegal = Z_NULL;
|
|
self->cpu.options = Z80_MODEL_ZILOG_NMOS;
|
|
}
|
|
|
|
|
|
void machine_power(Machine *self, zbool state) {
|
|
if (state)
|
|
{
|
|
self->cycles = 0;
|
|
memset(self->memory, 0, MEMORY_SIZE);
|
|
}
|
|
|
|
z80_power(&self->cpu, state);
|
|
}
|
|
|
|
|
|
void machine_reset(Machine *self) {
|
|
z80_instant_reset(&self->cpu);
|
|
}
|
|
|
|
void machine_run(Machine *self) {
|
|
z80_run(&self->cpu, Z80_MAXIMUM_CYCLES);
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
// Parse arguments
|
|
if (argc < 2) {
|
|
printf("Usage: %s [romFile]\n", argv[0]);
|
|
exit(0);
|
|
}
|
|
char* romFilePath = argv[1];
|
|
|
|
// Setup virtual Pat80 computer
|
|
Z80 pat80Cpu = {};
|
|
Machine pat80 = {
|
|
/*zusize*/ .cycles = 0,
|
|
/*Z80*/ .cpu = pat80Cpu
|
|
};
|
|
|
|
machine_initialize(&pat80);
|
|
machine_power(&pat80, Z_TRUE);
|
|
|
|
// Load ROM into memory
|
|
FILE *romFile;
|
|
romFile = fopen(romFilePath,"rb");
|
|
if (romFile == NULL) {
|
|
printf("Unable to open rom file at %s", romFilePath);
|
|
exit(1);
|
|
}
|
|
fread(&pat80.memory,ROM_SIZE,1,romFile); // load rom from file into memory, up >
|
|
fclose(romFile);
|
|
|
|
// Init ncurses
|
|
initscr(); // Start curses mode
|
|
raw(); // Line buffering disabled (get character without waiting for ENTER key)
|
|
keypad(stdscr, TRUE); // We get F1, F2 etc..
|
|
noecho(); // Don't echo() while we do getch
|
|
scrollok(stdscr, TRUE); // Allow scrolling when reached end of window
|
|
|
|
// Start emulated computer
|
|
machine_reset(&pat80);
|
|
machine_run(&pat80);
|
|
|
|
// Stop ncurses
|
|
endwin(); /* End curses mode */
|
|
return 0;
|
|
}
|