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Refactor ROM loading, SMB works with 261 scanlines
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@scottferg
scottferg committed Sep 16, 2012
1 parent 2750c2f commit f35bf0a
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Showing 4 changed files with 66 additions and 46 deletions.
2 changes: 0 additions & 2 deletions machine.go
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Original file line number Diff line number Diff line change
Expand Up @@ -57,8 +57,6 @@ func main() {
go JoypadListen()
go video.Render()

cpu.Verbose = true

for running {
cycles := cpu.Step()

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2 changes: 1 addition & 1 deletion memory.go
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Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,7 @@ func (m *Memory) Write(address interface{}, val Word) error {
controller.Write(val)
} else if a >= 0x8000 && a <= 0xFFFF {
// MMC1
//rom.Write(val, a)
rom.Write(val, a)
return nil
}

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2 changes: 1 addition & 1 deletion ppu.go
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Original file line number Diff line number Diff line change
Expand Up @@ -269,7 +269,7 @@ func (p *Ppu) Step() {
p.clearStatus(StatusVblankStarted)
} else if p.Cycle == 304 {
// Copy scroll latch into VRAMADDR register
p.VramAddress = (p.VramAddress & ^0x41F) | (p.VramLatch & 0x41F)
p.VramAddress = (p.VramAddress) | (p.VramLatch & 0x41F)
// p.VramAddress = p.VramLatch
}
}
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106 changes: 64 additions & 42 deletions rom.go
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Original file line number Diff line number Diff line change
Expand Up @@ -7,16 +7,16 @@ import (
)

type Mapper interface {
WriteRamBank(dest int, length int, offset int)
WriteRamBank(bank, dest int)
WriteVramBank(dest int, length int, offset int)
Write(v Word, a int)
Init(rom []byte) error
}

type Rom struct {
PrgFlag Word
ChrRomCount int
Data []byte
PrgBankCount int
ChrRomCount int
Data []byte

// TODO: MMC1
Buffer int
Expand All @@ -38,9 +38,9 @@ type Unrom Rom

// TODO: HOLY SHIT

func (r *Nrom) WriteRamBank(dest int, length int, offset int) {
for i := 0; i < length; i++ {
Ram.Write(i+dest, Word(r.Data[i+offset]))
func (r *Nrom) WriteRamBank(bank, dest int) {
for i := 0; i < 0x4000; i++ {
Ram.Write(i+dest, r.RomBanks[bank][i])
}
}

Expand All @@ -50,9 +50,9 @@ func (r *Nrom) WriteVramBank(dest int, length int, offset int) {
}
}

func (r *Mmc1) WriteRamBank(dest int, length int, offset int) {
for i := 0; i < length; i++ {
Ram.Write(i+dest, Word(r.Data[i+offset]))
func (r *Mmc1) WriteRamBank(bank, dest int) {
for i := 0; i < 0x4000; i++ {
Ram.Write(i+dest, r.RomBanks[bank][i])
}
}

Expand All @@ -62,7 +62,7 @@ func (r *Mmc1) WriteVramBank(dest int, length int, offset int) {
}
}

func (r *Unrom) WriteRamBank(dest int, length int, bank int) {
func (r *Unrom) WriteRamBank(bank, dest int) {
for i := 0; i < 0x4000; i++ {
Ram.Write(i+dest, r.RomBanks[bank][i])
}
Expand All @@ -81,7 +81,7 @@ func (r *Nrom) Write(v Word, a int) {
}

func (r *Nrom) Init(rom []byte) error {
r.PrgFlag = Word(rom[4])
r.PrgBankCount = int(rom[4])
r.ChrRomCount = int(rom[5])

switch rom[6] & 0x1 {
Expand All @@ -96,19 +96,33 @@ func (r *Nrom) Init(rom []byte) error {
// ROM data dests at byte 16
r.Data = rom[16:]

r.WriteRamBank(0x8000, 0x4000, 0x0)
fmt.Printf("PRG-ROM Count: %d\n", r.PrgBankCount)
r.RomBanks = make(map[int][]Word)

fmt.Printf("PRG-ROM Count: %d\n", r.PrgFlag)
switch r.PrgFlag {
fmt.Printf("Length of banks: %d\n", (len(r.Data) / 0x4000))

bankCount := (len(r.Data) / 0x4000)
for i := 0; i < bankCount; i++ {
// Move 16kb chunk to 16kb bank
bank := make([]Word, 0x4000)
for x := 0; x < 0x4000; x++ {
bank[x] = Word(r.Data[(0x4000*i)+x])
}

r.RomBanks[i] = bank
}

switch r.PrgBankCount {
case 0x01:
r.WriteRamBank(0x8000, 0x4000, 0x0)
r.WriteRamBank(0xC000, 0x4000, 0x0)
r.WriteRamBank(0, 0x8000)
r.WriteRamBank(0, 0xC000)

if r.ChrRomCount != 0 {
r.WriteVramBank(0x0000, 0x2000, 0x4000)
}
case 0x02:
r.WriteRamBank(0xC000, 0x4000, 0x4000)
r.WriteRamBank(0, 0x8000)
r.WriteRamBank(1, 0xC000)
r.WriteVramBank(0x0000, 0x2000, 0x8000)
}

Expand Down Expand Up @@ -210,7 +224,7 @@ func (r *Mmc1) SetRegister(reg int, v int) {

var bank int

if r.PrgFlag >= 32 {
if r.PrgBankCount >= 32 {
// 1024kb Cartridge
if r.VromSwitchingSize == 0 {
if r.RomSelectionReg0 == 1 {
Expand All @@ -219,7 +233,7 @@ func (r *Mmc1) SetRegister(reg int, v int) {
} else {
baseBank = (r.RomSelectionReg0 | (r.RomSelectionReg1 << 0x1)) << 0x3
}
} else if r.PrgFlag >= 16 {
} else if r.PrgBankCount >= 16 {
if r.RomSelectionReg0 == 1 {
baseBank = 8
}
Expand Down Expand Up @@ -257,7 +271,7 @@ func (r *Mmc1) RegisterNumber(a int) int {
}

func (r *Mmc1) Init(rom []byte) error {
r.PrgFlag = Word(rom[4])
r.PrgBankCount = int(rom[4])
r.ChrRomCount = int(rom[5])

switch rom[6] & 0x1 {
Expand All @@ -271,19 +285,30 @@ func (r *Mmc1) Init(rom []byte) error {

r.Data = rom[16:]

fmt.Printf("PRG-ROM Count: %d\n", r.PrgFlag)
fmt.Printf("PRG-ROM Count: %d\n", r.PrgBankCount)
r.RomBanks = make(map[int][]Word)
for i := 0; i < (r.PrgBankCount * 0x4000); i++ {
// Move 16kb chunk to 16kb bank
bank := make([]Word, 0x4000)
for x := 0; x < 0x4000; x++ {
bank[x] = Word(r.Data[(0x4000*i)+x])
}

r.RomBanks[i] = bank
}

// Write the first ROM bank
r.WriteRamBank(0x8000, 0x4000, 0x0)
r.WriteRamBank(0, 0x8000)
// and the last ROM bank
r.WriteRamBank(0xC000, 0x4000, len(r.Data)-0x4000)
r.WriteRamBank(7, 0xC000)

// r.WriteVramBank(0x0000, 0x2000, 0x0)

return nil
}

func (r *Unrom) Init(rom []byte) error {
r.PrgFlag = Word(rom[4])
r.PrgBankCount = int(rom[4])
r.ChrRomCount = int(rom[5])

switch rom[6] & 0x1 {
Expand All @@ -297,28 +322,25 @@ func (r *Unrom) Init(rom []byte) error {

// ROM data dests at byte 16
r.Data = rom[16:]
r.RomBanks = make(map[int][]Word)

fmt.Printf("PRG-ROM Count: %d\n", r.PrgFlag)
fmt.Printf("PRG-ROM Count: %d\n", r.PrgBankCount)

r.RomBanks = make(map[int][]Word)
for i := 0; i < (len(r.Data) / 0x4000); i++ {
fmt.Printf("Length of banks: %d\n", (len(r.Data) / 0x4000))
// Move 16kb chunk to 16kb bank
bank := make([]Word, 0x4000)
for x := 0; x < 0x4000; x++ {
fmt.Printf("Reading: 0x%X\n", (0x4000*i)+x)
bank[x] = Word(r.Data[(0x4000*i)+x])
}
bankCount := (len(r.Data) / 0x4000)
for i := 0; i < bankCount; i++ {
// Move 16kb chunk to 16kb bank
bank := make([]Word, 0x4000)
for x := 0; x < 0x4000; x++ {
bank[x] = Word(r.Data[(0x4000*i)+x])
}

r.RomBanks[i] = bank
r.RomBanks[i] = bank
}

fmt.Printf("Length: %d\n", len(r.RomBanks))

// Write the first ROM bank
r.WriteRamBank(0x8000, 0x0, 0)
r.WriteRamBank(0, 0x8000)
// and the last ROM bank
r.WriteRamBank(0xC000, 0x0, 7)
r.WriteRamBank(7, 0xC000)

fmt.Printf("VROM: %d\n", r.ChrRomCount)
// r.WriteVramBank(0x0000, 0x2000, 0x8000)
Expand All @@ -327,8 +349,8 @@ func (r *Unrom) Init(rom []byte) error {
}

func (r *Unrom) Write(v Word, a int) {
fmt.Printf("Loading new bank: %d\n", v)
r.WriteRamBank(0x8000, 0x0, int(v))
fmt.Printf("Loading new bank: %d\n", v)
r.WriteRamBank(int(v), 0x8000)
}

func LoadRom(rom []byte) (r Mapper, e error) {
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