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-rw-r--r--cpu.c91
-rw-r--r--cpu.h2
-rw-r--r--opcodes.h106
3 files changed, 111 insertions, 88 deletions
diff --git a/cpu.c b/cpu.c
index e3bb7d5..039337f 100644
--- a/cpu.c
+++ b/cpu.c
@@ -128,8 +128,8 @@ opcode_mem(enum addressing_mode mode)
break;
case AM_REL:
val = arg + regs.pc;
- if ((regs.pc + 1) & 0xFF00 != val & 0xFF00)
- page_crossed = true;
+ if (((regs.pc + 1) & 0xFF00) != (val & 0xFF00))
+ val -= 0x0100;
break;
case AM_IMM:
case AM_ABS:
@@ -703,133 +703,158 @@ TYA(uint16_t arg)
void
AAC(uint16_t arg)
{
- NOP(0);
+ AND(arg);
+
+ regs.status.carry = regs.status.negative;
}
void
-AAX(uint16_t arg)
+SAX(uint16_t arg)
{
- NOP(0);
+ uint8_t tmp = regs.x & regs.a;
+ memwrite(arg, tmp);
}
void
ARR(uint16_t arg)
{
- NOP(0);
+ uint8_t tmp = arg & regs.a;
+
+ AND(arg);
+ ROR_acc(0);
+
+ if ((tmp & (1 << 5)) != 0 && (tmp & (1 << 6)) != 0)
+ SEC(0), CLV(0);
+ else if ((tmp & (1 << 5)) == 0 && (tmp & (1 << 6)) == 0)
+ CLC(0), CLV(0);
+ else if ((tmp & (1 << 5)) != 0)
+ CLC(0), regs.status.overflow = 1;
+ else if ((tmp & (1 << 6)) != 0)
+ SEC(0), regs.status.overflow = 1;
}
void
ASR(uint16_t arg)
{
- NOP(0);
+ AND(arg);
+ LSR_acc(0);
}
void
ATX(uint16_t arg)
{
- NOP(0);
+ AND(arg);
+ TAX(0);
}
void
AXA(uint16_t arg)
{
- NOP(0);
+ uint8_t tmp = regs.x & regs.a & 7;
+ memwrite(arg, tmp);
}
void
AXS(uint16_t arg)
{
- NOP(0);
+ regs.x &= regs.a;
+ regs.x -= arg;
+
+ regs.status.carry = arg <= regs.x;
+ STATUS_UPDATE_NZ(regs.x);
}
void
DCP(uint16_t arg)
{
- NOP(0);
-}
+ uint8_t tmp = peek(arg) - 1;
+ memwrite(arg, tmp);
-void
-DOP(uint16_t arg)
-{
- NOP(0);
+ regs.status.carry = tmp <= regs.a;
+ STATUS_UPDATE_NZ(tmp);
}
void
ISC(uint16_t arg)
{
- NOP(0);
+ INC(arg);
+ SBC(peek(arg));
}
void
KIL(uint16_t arg)
{
+ /* TODO: figure out how to stop interpret(), I guess with global bool */
NOP(0);
}
void
LAR(uint16_t arg)
{
- NOP(0);
+ regs.a = regs.x = regs.sp = regs.a & regs.sp;
+
+ STATUS_UPDATE_NZ(regs.a);
}
void
LAX(uint16_t arg)
{
- NOP(0);
+ LDA(arg);
+ LDX(arg);
}
void
RLA(uint16_t arg)
{
- NOP(0);
+ ROL(arg);
+ AND(arg);
}
void
RRA(uint16_t arg)
{
- NOP(0);
+ ROR(arg);
+ ADC(peek(arg));
}
void
SLO(uint16_t arg)
{
- NOP(0);
+ ASL(arg);
+ ORA(arg);
}
void
SRE(uint16_t arg)
{
- NOP(0);
+ LSR(arg);
+ EOR(arg);
}
void
SXA(uint16_t arg)
{
- NOP(0);
+ memwrite(arg, regs.x & ((arg & 0xFF00) + 1));
}
void
SYA(uint16_t arg)
{
- NOP(0);
-}
-
-void
-TOP(uint16_t arg)
-{
- NOP(0);
+ memwrite(arg, regs.x & ((arg & 0xFF00) + 1));
}
void
XAA(uint16_t arg)
{
+ /* TODO: apparently the exact operation is unknown */
NOP(0);
}
void
XAS(uint16_t arg)
{
- NOP(0);
+ regs.sp = regs.a & regs.x;
+ memwrite(arg, regs.sp & ((arg & 0xFF00) + 1));
}
static void
@@ -877,8 +902,6 @@ interpret(void)
printf("$%02X,Y", arg);
break;
case AM_REL:
- printf("$%04X", regs.pc + arg);
- break;
case AM_ABS:
printf("$%04X", arg);
break;
diff --git a/cpu.h b/cpu.h
index b7cab89..3002573 100644
--- a/cpu.h
+++ b/cpu.h
@@ -64,7 +64,7 @@ void TYA(uint16_t arg);
/* UNOFFICIAL OPCODES */
void AAC(uint16_t arg);
-void AAX(uint16_t arg);
+void SAX(uint16_t arg);
void ARR(uint16_t arg);
void ASR(uint16_t arg);
void ATX(uint16_t arg);
diff --git a/opcodes.h b/opcodes.h
index ca0d1cc..020e8f3 100644
--- a/opcodes.h
+++ b/opcodes.h
@@ -189,23 +189,23 @@ struct opcode opcodes[0x100] = {
/* unofficial opcodes: https://www.nesdev.org/undocumented_opcodes.txt */
[0x0B] = { "AAC", AAC, 2, 2, false, false, false, true, AM_IMM },
[0x2B] = { "AAC", AAC, 2, 2, false, false, false, true, AM_IMM },
- [0x87] = { "AAX", AAX, 2, 3, false, false, false, true, AM_ZP },
- [0x97] = { "AAX", AAX, 2, 4, false, false, false, true, AM_ZP_Y },
- [0x83] = { "AAX", AAX, 2, 6, false, false, false, true, AM_IND_X },
- [0x8F] = { "AAX", AAX, 3, 4, false, false, false, true, AM_ABS },
+ [0x87] = { "SAX", SAX, 2, 3, false, true, false, true, AM_ZP },
+ [0x97] = { "SAX", SAX, 2, 4, false, true, false, true, AM_ZP_Y },
+ [0x83] = { "SAX", SAX, 2, 6, false, true, false, true, AM_IND_X },
+ [0x8F] = { "SAX", SAX, 3, 4, false, true, false, true, AM_ABS },
[0x6B] = { "ARR", ARR, 2, 2, false, false, false, true, AM_IMM },
[0x4B] = { "ASR", ASR, 2, 2, false, false, false, true, AM_IMM },
[0xAB] = { "ATX", ATX, 2, 2, false, false, false, true, AM_IMM },
- [0x9F] = { "AXA", AXA, 3, 5, false, false, false, true, AM_ABS_Y },
- [0x93] = { "AXA", AXA, 2, 6, false, false, false, true, AM_IND_Y },
+ [0x9F] = { "AXA", AXA, 3, 5, false, true, false, true, AM_ABS_Y },
+ [0x93] = { "AXA", AXA, 2, 6, false, true, false, true, AM_IND_Y },
[0xCB] = { "AXS", AXS, 2, 2, false, false, false, true, AM_IMM },
- [0xC7] = { "DCP", DCP, 2, 5, false, false, false, true, AM_ZP },
- [0xD7] = { "DCP", DCP, 2, 6, false, false, false, true, AM_ZP_X },
- [0xCF] = { "DCP", DCP, 3, 6, false, false, false, true, AM_ABS },
- [0xDF] = { "DCP", DCP, 3, 7, false, false, false, true, AM_ABS_X },
- [0xDB] = { "DCP", DCP, 3, 7, false, false, false, true, AM_ABS_Y },
- [0xC3] = { "DCP", DCP, 2, 8, false, false, false, true, AM_IND_X },
- [0xD3] = { "DCP", DCP, 2, 8, false, false, false, true, AM_IND_Y },
+ [0xC7] = { "DCP", DCP, 2, 5, false, true, false, true, AM_ZP },
+ [0xD7] = { "DCP", DCP, 2, 6, false, true, false, true, AM_ZP_X },
+ [0xCF] = { "DCP", DCP, 3, 6, false, true, false, true, AM_ABS },
+ [0xDF] = { "DCP", DCP, 3, 7, false, true, false, true, AM_ABS_X },
+ [0xDB] = { "DCP", DCP, 3, 7, false, true, false, true, AM_ABS_Y },
+ [0xC3] = { "DCP", DCP, 2, 8, false, true, false, true, AM_IND_X },
+ [0xD3] = { "DCP", DCP, 2, 8, false, true, false, true, AM_IND_Y },
[0x04] = { "NOP", NOP, 2, 3, true, false, false, true, AM_ZP },
[0x14] = { "NOP", NOP, 2, 4, true, false, false, true, AM_ZP_X },
[0x34] = { "NOP", NOP, 2, 4, true, false, false, true, AM_ZP_X },
@@ -217,9 +217,9 @@ struct opcode opcodes[0x100] = {
[0x82] = { "NOP", NOP, 2, 2, false, false, false, true, AM_IMM },
[0x89] = { "NOP", NOP, 2, 2, false, false, false, true, AM_IMM },
[0xC2] = { "NOP", NOP, 2, 2, false, false, false, true, AM_IMM },
- [0xD4] = { "NOP", NOP, 2, 4, false, false, false, true, AM_ZP_X },
+ [0xD4] = { "NOP", NOP, 2, 4, true, false, false, true, AM_ZP_X },
[0xE2] = { "NOP", NOP, 2, 2, false, false, false, true, AM_IMM },
- [0xF4] = { "NOP", NOP, 2, 4, false, false, false, true, AM_ZP_X },
+ [0xF4] = { "NOP", NOP, 2, 4, true, false, false, true, AM_ZP_X },
[0xE7] = { "ISC", ISC, 2, 5, false, false, false, true, AM_ZP },
[0xF7] = { "ISC", ISC, 2, 6, false, false, false, true, AM_ZP_X },
[0xEF] = { "ISC", ISC, 3, 6, false, false, false, true, AM_ABS },
@@ -239,50 +239,50 @@ struct opcode opcodes[0x100] = {
[0xB2] = { "KIL", KIL, 1, 0, false, false, false, true, AM_NONE },
[0xD2] = { "KIL", KIL, 1, 0, false, false, false, true, AM_NONE },
[0xF2] = { "KIL", KIL, 1, 0, false, false, false, true, AM_NONE },
- [0xBB] = { "LAR", LAR, 3, 4, false, false, true, true, AM_ABS_Y },
- [0xA7] = { "LAX", LAX, 2, 3, false, false, false, true, AM_ZP },
- [0xB7] = { "LAX", LAX, 2, 4, false, false, false, true, AM_ZP_Y },
- [0xAF] = { "LAX", LAX, 3, 4, false, false, false, true, AM_ABS },
- [0xBF] = { "LAX", LAX, 3, 4, false, false, true, true, AM_ABS_Y },
- [0xA3] = { "LAX", LAX, 2, 6, false, false, false, true, AM_IND_X },
- [0xB3] = { "LAX", LAX, 2, 5, false, false, true, true, AM_IND_Y },
+ [0xBB] = { "LAR", LAR, 3, 4, true, false, true, true, AM_ABS_Y },
+ [0xA7] = { "LAX", LAX, 2, 3, true, false, false, true, AM_ZP },
+ [0xB7] = { "LAX", LAX, 2, 4, true, false, false, true, AM_ZP_Y },
+ [0xAF] = { "LAX", LAX, 3, 4, true, false, false, true, AM_ABS },
+ [0xBF] = { "LAX", LAX, 3, 4, true, false, true, true, AM_ABS_Y },
+ [0xA3] = { "LAX", LAX, 2, 6, true, false, false, true, AM_IND_X },
+ [0xB3] = { "LAX", LAX, 2, 5, true, false, true, true, AM_IND_Y },
[0x1A] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
[0x3A] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
[0x5A] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
[0x7A] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
[0xDA] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
[0xFA] = { "NOP", NOP, 1, 2, false, false, false, true, AM_NONE },
- [0x27] = { "RLA", RLA, 2, 5, false, false, false, true, AM_ZP },
- [0x37] = { "RLA", RLA, 2, 6, false, false, false, true, AM_ZP_X },
- [0x2F] = { "RLA", RLA, 3, 6, false, false, false, true, AM_ABS },
- [0x3F] = { "RLA", RLA, 3, 7, false, false, false, true, AM_ABS_X },
- [0x3B] = { "RLA", RLA, 3, 7, false, false, false, true, AM_ABS_Y },
- [0x23] = { "RLA", RLA, 2, 8, false, false, false, true, AM_IND_X },
- [0x33] = { "RLA", RLA, 2, 8, false, false, false, true, AM_IND_Y },
- [0x67] = { "RRA", RRA, 2, 5, false, false, false, true, AM_ZP },
- [0x77] = { "RRA", RRA, 2, 6, false, false, false, true, AM_ZP_X },
- [0x6F] = { "RRA", RRA, 3, 6, false, false, false, true, AM_ABS },
- [0x7F] = { "RRA", RRA, 3, 7, false, false, false, true, AM_ABS_X },
- [0x7B] = { "RRA", RRA, 3, 7, false, false, false, true, AM_ABS_Y },
- [0x63] = { "RRA", RRA, 2, 8, false, false, false, true, AM_IND_X },
- [0x73] = { "RRA", RRA, 2, 8, false, false, false, true, AM_IND_Y },
+ [0x27] = { "RLA", RLA, 2, 5, true, true, false, true, AM_ZP },
+ [0x37] = { "RLA", RLA, 2, 6, true, true, false, true, AM_ZP_X },
+ [0x2F] = { "RLA", RLA, 3, 6, true, true, false, true, AM_ABS },
+ [0x3F] = { "RLA", RLA, 3, 7, true, true, false, true, AM_ABS_X },
+ [0x3B] = { "RLA", RLA, 3, 7, true, true, false, true, AM_ABS_Y },
+ [0x23] = { "RLA", RLA, 2, 8, true, true, false, true, AM_IND_X },
+ [0x33] = { "RLA", RLA, 2, 8, true, true, false, true, AM_IND_Y },
+ [0x67] = { "RRA", RRA, 2, 5, true, true, false, true, AM_ZP },
+ [0x77] = { "RRA", RRA, 2, 6, true, true, false, true, AM_ZP_X },
+ [0x6F] = { "RRA", RRA, 3, 6, true, true, false, true, AM_ABS },
+ [0x7F] = { "RRA", RRA, 3, 7, true, true, false, true, AM_ABS_X },
+ [0x7B] = { "RRA", RRA, 3, 7, true, true, false, true, AM_ABS_Y },
+ [0x63] = { "RRA", RRA, 2, 8, true, true, false, true, AM_IND_X },
+ [0x73] = { "RRA", RRA, 2, 8, true, true, false, true, AM_IND_Y },
[0xEB] = { "SBC", SBC, 2, 2, false, false, false, true, AM_IMM },
- [0x07] = { "SLO", SLO, 2, 5, false, false, false, true, AM_ZP },
- [0x17] = { "SLO", SLO, 2, 6, false, false, false, true, AM_ZP_X },
- [0x0F] = { "SLO", SLO, 3, 6, false, false, false, true, AM_ABS },
- [0x1F] = { "SLO", SLO, 3, 7, false, false, false, true, AM_ABS_X },
- [0x1B] = { "SLO", SLO, 3, 7, false, false, false, true, AM_ABS_Y },
- [0x03] = { "SLO", SLO, 2, 8, false, false, false, true, AM_IND_X },
- [0x13] = { "SLO", SLO, 2, 8, false, false, false, true, AM_IND_Y },
- [0x47] = { "SRE", SRE, 2, 5, false, false, false, true, AM_ZP },
- [0x57] = { "SRE", SRE, 2, 6, false, false, false, true, AM_ZP_X },
- [0x4F] = { "SRE", SRE, 3, 6, false, false, false, true, AM_ABS },
- [0x5F] = { "SRE", SRE, 3, 7, false, false, false, true, AM_ABS_X },
- [0x5B] = { "SRE", SRE, 3, 7, false, false, false, true, AM_ABS_Y },
- [0x43] = { "SRE", SRE, 2, 8, false, false, false, true, AM_IND_X },
- [0x53] = { "SRE", SRE, 2, 8, false, false, false, true, AM_IND_Y },
- [0x9E] = { "SXA", SXA, 3, 5, false, false, false, true, AM_ABS_Y },
- [0x9C] = { "SYA", SYA, 3, 5, false, false, false, true, AM_ABS_X },
+ [0x07] = { "SLO", SLO, 2, 5, true, true, false, true, AM_ZP },
+ [0x17] = { "SLO", SLO, 2, 6, true, true, false, true, AM_ZP_X },
+ [0x0F] = { "SLO", SLO, 3, 6, true, true, false, true, AM_ABS },
+ [0x1F] = { "SLO", SLO, 3, 7, true, true, false, true, AM_ABS_X },
+ [0x1B] = { "SLO", SLO, 3, 7, true, true, false, true, AM_ABS_Y },
+ [0x03] = { "SLO", SLO, 2, 8, true, true, false, true, AM_IND_X },
+ [0x13] = { "SLO", SLO, 2, 8, true, true, false, true, AM_IND_Y },
+ [0x47] = { "SRE", SRE, 2, 5, true, true, false, true, AM_ZP },
+ [0x57] = { "SRE", SRE, 2, 6, true, true, false, true, AM_ZP_X },
+ [0x4F] = { "SRE", SRE, 3, 6, true, true, false, true, AM_ABS },
+ [0x5F] = { "SRE", SRE, 3, 7, true, true, false, true, AM_ABS_X },
+ [0x5B] = { "SRE", SRE, 3, 7, true, true, false, true, AM_ABS_Y },
+ [0x43] = { "SRE", SRE, 2, 8, true, true, false, true, AM_IND_X },
+ [0x53] = { "SRE", SRE, 2, 8, true, true, false, true, AM_IND_Y },
+ [0x9E] = { "SXA", SXA, 3, 5, false, true, false, true, AM_ABS_Y },
+ [0x9C] = { "SYA", SYA, 3, 5, false, true, false, true, AM_ABS_X },
[0x0C] = { "NOP", NOP, 3, 4, true, false, false, true, AM_ABS },
[0x1C] = { "NOP", NOP, 3, 4, true, false, true, true, AM_ABS_X },
[0x3C] = { "NOP", NOP, 3, 4, true, false, true, true, AM_ABS_X },
@@ -291,5 +291,5 @@ struct opcode opcodes[0x100] = {
[0xDC] = { "NOP", NOP, 3, 4, true, false, true, true, AM_ABS_X },
[0xFC] = { "NOP", NOP, 3, 4, true, false, true, true, AM_ABS_X },
[0x8B] = { "XAA", XAA, 2, 2, false, false, false, true, AM_IMM },
- [0x9B] = { "XAS", XAS, 3, 5, false, false, false, true, AM_ABS_Y },
+ [0x9B] = { "XAS", XAS, 3, 5, false, true, false, true, AM_ABS_Y },
};
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-27 15:55:20 +0000