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-rw-r--r--src/mos6502.rs33
-rw-r--r--src/ppu.rs21
2 files changed, 30 insertions, 24 deletions
diff --git a/src/mos6502.rs b/src/mos6502.rs
index fdce0ab..e95910f 100644
--- a/src/mos6502.rs
+++ b/src/mos6502.rs
@@ -232,6 +232,13 @@ macro_rules! read16 {
$mem.read($laddr)));
}
+macro_rules! read16wrap {
+ ($mem: expr, $laddr: expr) => ({
+ let naddr = ($laddr & 0xff00) | (($laddr as u8).wrapping_add(1) as u16);
+ make16!($mem.read(naddr), $mem.read($laddr))
+ });
+}
+
mod ops {
use memory::VMem;
use mos6502::*;
@@ -392,13 +399,13 @@ mod ops {
fn rol(cpu: &mut CPU) {
let res = match cpu.acc {
true => {
- let t = (cpu.a as u16) << 1;
- cpu.a = t as u8 | cpu.get_carry();
+ let t = ((cpu.a as u16) << 1) | (cpu.get_carry() as u16);
+ cpu.a = t as u8;
t
},
false => {
- let t = (cpu.mem.read(cpu.ea) as u16) << 1;
- cpu.mem.write(cpu.ea, t as u8 | cpu.get_carry());
+ let t = ((cpu.mem.read(cpu.ea) as u16) << 1) | (cpu.get_carry() as u16);
+ cpu.mem.write(cpu.ea, t as u8);
t
}};
let mut status = cpu.status & !(CARRY_FLAG | ZERO_FLAG | NEG_FLAG);
@@ -413,15 +420,15 @@ mod ops {
let res = match cpu.acc {
true => {
let old = cpu.a;
- let t = old >> 1;
- cpu.a = t as u8 | (cpu.get_carry() << 7);
+ let t = (old >> 1) | (cpu.get_carry() << 7);
+ cpu.a = t as u8;
status |= (old & 1) as u8; /* carry flag */
t
},
false => {
let old = cpu.mem.read(cpu.ea);
- let t = old >> 1;
- cpu.mem.write(cpu.ea, t as u8 | (cpu.get_carry() << 7));
+ let t = (old >> 1) | (cpu.get_carry() << 7);
+ cpu.mem.write(cpu.ea, t as u8);
status |= (old & 1) as u8; /* carry flag */
t
}};
@@ -649,17 +656,17 @@ mod addr {
fn ind(cpu: &mut CPU) -> u8 {
let addr = read16!(cpu.mem, cpu.opr);
- cpu.ea = read16!(cpu.mem, addr); 0
+ cpu.ea = read16wrap!(cpu.mem, addr); 0
}
fn xin(cpu: &mut CPU) -> u8 {
- cpu.ea = read16!(cpu.mem,
+ cpu.ea = read16wrap!(cpu.mem,
cpu.mem.read(cpu.opr)
.wrapping_add(cpu.x) as u16) as u16; 0
}
fn iny(cpu: &mut CPU) -> u8 {
- let base = read16!(cpu.mem, cpu.mem.read(cpu.opr) as u16);
+ let base = read16wrap!(cpu.mem, cpu.mem.read(cpu.opr) as u16);
let sum = (base & 0xff) + (cpu.y as u16);
cpu.ea = (base & 0xff00).wrapping_add(sum);
(sum >> 8) as u8 /* boundary cross if carry */
@@ -747,7 +754,7 @@ impl<'a> CPU<'a> {
} else {
let pc = self.pc;
let opcode = self.mem.read(pc) as usize;
- /*
+ /*
let len = INST_LENGTH[opcode];
let mut code = vec![0; len as usize];
for i in 0..len as u16 {
@@ -756,7 +763,7 @@ impl<'a> CPU<'a> {
println!("0x{:04x} {} a:{:02x} x:{:02x} y:{:02x} s: {:02x} sp: {:02x}",
pc, disasm::parse(opcode as u8, &code[1..]),
self.a, self.x, self.y, self.status, self.sp);
- */
+ */
/* update opr pointing to operands of current inst */
self.opr = pc.wrapping_add(1);
/* update program counter pointing to next inst */
diff --git a/src/ppu.rs b/src/ppu.rs
index 62a8261..9938373 100644
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -447,7 +447,7 @@ impl<'a> PPU<'a> {
let ppustatus = 0xa0;
let oamaddr = 0x00;
let buffered_read = 0x00;
- let cycle = 370;
+ let cycle = 340;
let scanline = 240;
PPU {
scanline,
@@ -478,7 +478,7 @@ impl<'a> PPU<'a> {
self.ppustatus = self.ppustatus & 0x80;
self.w = false;
self.buffered_read = 0x00;
- self.cycle = 370;
+ self.cycle = 340;
self.scanline = 240;
}
@@ -528,18 +528,11 @@ impl<'a> PPU<'a> {
self.reset_cx();
self.fetch_sprite();
}
- if pre_line {
- if cycle == 1 {
- /* clear vblank, sprite zero hit & overflow */
- self.ppustatus &= !(PPU::FLAG_VBLANK |
- PPU::FLAG_SPRITE_ZERO | PPU::FLAG_OVERFLOW);
- self.bg_pixel = 0
- } else if cycle == 339 && self.f {
+ if pre_line && cycle == 339 && self.f {
self.scanline = 0;
self.cycle = 0;
self.f = !self.f;
return false;
- }
}
}
} else {
@@ -549,11 +542,17 @@ impl<'a> PPU<'a> {
self.ppustatus |= PPU::FLAG_VBLANK;
}
self.scr.render();
- self.cycle += 1;
+ self.cycle = 2;
self.early_read = false;
return !self.early_read && self.get_flag_nmi(); /* trigger cpu's NMI */
}
}
+ if pre_line && cycle == 1 {
+ /* clear vblank, sprite zero hit & overflow */
+ self.ppustatus &= !(PPU::FLAG_VBLANK |
+ PPU::FLAG_SPRITE_ZERO | PPU::FLAG_OVERFLOW);
+ self.bg_pixel = 0;
+ }
self.cycle += 1;
if self.cycle > 340 {
self.cycle = 0;