lauchmelder/NESEmulator
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added more instructions

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This commit is contained in:
Lauchmelder 2021-10-23 00:47:33 +02:00
parent f872e19707
commit a345421963
6 changed files with 558 additions and 39 deletions
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19
NES Emulator/bus.c
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@ -1,6 +1,7 @@
#include "bus.h"
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include "cpu.h"
#include "cartridge.h"
@ -21,6 +22,15 @@ struct Bus* createBus()
fprintf(stderr, "Failed to allocate memory for NES RAM, aborting.");
exit(1);
}
memset(bus->ram, 0x00, 0x800);
bus->io = (Byte*)malloc(0x18);
if (bus->io == NULL)
{
fprintf(stderr, "Failed to allocate memory for NES I/O, aborting.");
exit(1);
}
memset(bus->ram, 0x00, 0x18);
// Create CPU and attach it
bus->cpu = createCPU(bus);
@ -38,6 +48,7 @@ void destroyBus(struct Bus* bus)
destroyCartridge(bus->cartridge);
destroyCPU(bus->cpu);
free(bus->io);
free(bus->ram);
free(bus);
}
@ -51,6 +62,10 @@ Byte readBus(struct Bus* bus, Word addr)
{
val = bus->ram[addr & 0x7FF];
}
else if (0x4000 <= addr && addr <= 0x4017) // I/O space
{
val = bus->io[addr - 0x4000];
}
else if (0x4020 <= addr && addr <= 0xFFFF) // Cartridge space
{
val = readCartridge(bus->cartridge, addr);
@ -71,6 +86,10 @@ void writeBus(struct Bus* bus, Word addr, Byte val)
{
bus->ram[addr & 0x7FF] = val;
}
else if (0x4000 <= addr && addr <= 0x4017) // I/O space
{
bus->io[addr - 0x4000] = val;
}
else if (0x4020 <= addr && addr <= 0xFFFF) // Cartridge space
{
writeCartridge(bus->cartridge, addr, val);