package goapple2 import ( "fmt" "io/ioutil" "log" "path/filepath" "strconv" "time" "github.com/zellyn/go6502/cpu" "github.com/zellyn/goapple2/cards" "github.com/zellyn/goapple2/videoscan" ) type PCActionType int const ( ActionDumpMem PCActionType = iota + 1 ActionLogRegisters ) type PCAction struct { Type PCActionType String string } // Apple II struct type Apple2 struct { mem [65536]byte cpu cpu.Cpu key byte // BUG(zellyn): make reads/writes atomic keys chan byte plotter videoscan.Plotter scanner *videoscan.Scanner Done bool lastRead byte cards [8]cards.Card "Peripheral cards" cardMask byte cardRomMask byte cardRomConflict bool "True if more than one card is handling the 2k ROM area" cardRomHandler byte card12kMask byte card12kConflict bool "True if more than one card is handling the 12k ROM area" card12kHandler byte cardTickerMask byte pcActions map[uint16][]PCAction } func NewApple2(p videoscan.Plotter, rom []byte, charRom [2048]byte) *Apple2 { a2 := Apple2{ // BUG(zellyn): this is not how the apple2 keyboard actually works keys: make(chan byte, 16), pcActions: make(map[uint16][]PCAction), } copy(a2.mem[len(a2.mem)-len(rom):len(a2.mem)], rom) a2.scanner = videoscan.NewScanner(&a2, p, charRom) a2.cpu = cpu.NewCPU(&a2, &a2, cpu.VERSION_6502) a2.cpu.Reset() return &a2 } func (a2 *Apple2) AddCard(card cards.Card) error { slot := card.Slot() slotbit := byte(1 << slot) if slotbit&a2.cardMask > 0 { return fmt.Errorf("Slot %d already has a card: %s", slot, a2.cards[slot]) } a2.cardMask |= slotbit if card.WantTicker() { a2.cardTickerMask |= slotbit } a2.cards[slot] = card return nil } func (a2 *Apple2) handleCardRom(address uint16, value byte, write bool) byte { return a2.EmptyRead() } func (a2 *Apple2) handleC00X(address uint16, value byte, write bool) byte { if address < 0xC080 { switch address & 0xC0F0 { // $C00X: Read keyboard case 0xC000: if a2.key&0x80 == 0 { select { case key := <-a2.keys: a2.key = key default: } } return a2.key // $C01X: Reset keyboard case 0xC010: a2.key &= 0x7F return a2.EmptyRead() } switch address { case 0xC050: // GRAPHICS fmt.Printf("$%04X: GRAPHICS\n", a2.cpu.PC()) a2.scanner.SetGraphics(true) case 0xC051: // TEXT fmt.Printf("$%04X: NO GRAPHICS\n", a2.cpu.PC()) a2.scanner.SetGraphics(false) case 0xC052: // NOMIX fmt.Printf("$%04X: NOMIX\n", a2.cpu.PC()) a2.scanner.SetMix(false) case 0xC053: // MIX fmt.Printf("$%04X: MIX\n", a2.cpu.PC()) a2.scanner.SetMix(true) case 0xC054: // PAGE 1 fmt.Printf("$%04X: PAGE1\n", a2.cpu.PC()) a2.scanner.SetPage(1) case 0xC055: // PAGE 2 fmt.Printf("$%04X: PAGE2\n", a2.cpu.PC()) a2.scanner.SetPage(2) case 0xC056: // LORES fmt.Printf("$%04X: LORES\n", a2.cpu.PC()) a2.scanner.SetHires(false) case 0xC057: // HIRES fmt.Printf("$%04X: HIRES\n", a2.cpu.PC()) a2.scanner.SetHires(true) } } if address < 0xC080 { return a2.EmptyRead() } if address < 0xC100 { slot := byte((address - 0xC080) >> 4) if a2.cards[slot] != nil { if write { a2.cards[slot].Write16(byte(address&0xF), value) return 0 } else { return a2.cards[slot].Read16(byte(address & 0xF)) } } return a2.EmptyRead() } if address < 0xC800 { slot := byte((address - 0xC000) >> 8) if a2.cards[slot] != nil { if write { a2.cards[slot].Write256(byte(address&0xFF), value) return 0 } else { return a2.cards[slot].Read256(byte(address & 0xFF)) } } return a2.EmptyRead() } // 0xCFFF disables 2k on all cards if address == 0xCFFF { for i := 0; a2.cardMask > 0; a2.cardMask >>= 1 { if a2.cardMask&1 > 0 { a2.cards[i].ROMDisabled() } i++ } return a2.EmptyRead() } // Only addresses left are 0xC800-0xCFFE if a2.cardRomMask == 0 { return a2.EmptyRead() } if a2.cardRomConflict { panic(fmt.Sprintf("More than one card trying to provide 2K ROM: Mask=$%02X", a2.cardRomMask)) } if write { a2.cards[a2.cardRomHandler].Write(address, value) return 0 } return a2.cards[a2.cardRomHandler].Read(address) } // EmptyRead returns the value last read from RAM, lingering on the bus. func (a2 *Apple2) EmptyRead() byte { return a2.lastRead } func (a2 *Apple2) Read(address uint16) byte { if address&0xF000 == 0xC000 { return a2.handleC00X(address, 0, false) } if address >= 0xD000 && a2.cardRomMask > 0 { if a2.card12kConflict { panic(fmt.Sprintf("More than one card trying to provide 12K ROM: Mask=$%02X", a2.card12kMask)) } a2.lastRead = a2.cards[a2.card12kHandler].Read(address) return a2.lastRead } a2.lastRead = a2.mem[address] return a2.lastRead } func (a2 *Apple2) RamRead(address uint16) byte { a2.lastRead = a2.mem[address] return a2.lastRead } func (a2 *Apple2) Write(address uint16, value byte) { if address >= 0xD000 { if a2.cardRomMask > 0 { if a2.card12kConflict { panic(fmt.Sprintf("More than one card trying to provide 12K ROM: Mask=$%02X", a2.card12kMask)) } a2.cards[a2.card12kHandler].Write(address, value) } return } if address&0xF000 == 0xC000 { a2.handleC00X(address, value, true) return } a2.mem[address] = value } func (a2 *Apple2) Keypress(key byte) { a2.keys <- key | 0x80 } func (a2 *Apple2) AddPCAction(address uint16, action PCAction) { a2.pcActions[address] = append(a2.pcActions[address], action) } func (a2 *Apple2) Step() error { if actions, ok := a2.pcActions[a2.cpu.PC()]; ok { for _, action := range actions { switch action.Type { case ActionDumpMem: a2.DumpRAM(action.String, true) case ActionLogRegisters: a2.LogRegisters() } } } return a2.cpu.Step() } func (a2 *Apple2) Tick() { a2.scanner.Scan1() tickerMask := a2.cardTickerMask for i := 0; i < 8 && tickerMask > 0; i++ { if tickerMask&1 == 1 { a2.cards[i].Tick() } tickerMask >>= 1 } } func (a2 *Apple2) Quit() { a2.Done = true } func (a2 *Apple2) HandleROM(onOff bool, slot byte) { if onOff { a2.cardRomMask |= (1 << slot) a2.cardRomHandler = slot } else { a2.cardRomMask &^= (1 << slot) } a2.cardRomConflict = a2.cardRomMask&(a2.cardRomMask-1) > 0 if !onOff && !a2.cardRomConflict && a2.cardRomMask > 0 { // Removed a card: figure out new handler for i := byte(0); i < 7; i++ { if 1< 0 if !onOff && !a2.card12kConflict && a2.card12kMask > 0 { // Removed a card: figure out new handler for i := byte(0); i < 7; i++ { if 1<