mirror of
https://github.com/ivanizag/izapple2.git
synced 2024-12-21 18:29:45 +00:00
118 lines
2.8 KiB
Go
118 lines
2.8 KiB
Go
package apple2
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import (
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"encoding/binary"
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"fmt"
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"io"
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)
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type ioC0Page struct {
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softSwitchesR [256]softSwitchR
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softSwitchesW [256]softSwitchW
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softSwitchesData [128]uint8
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keyboard KeyboardProvider
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speaker SpeakerProvider
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apple2 *Apple2
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}
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type softSwitchR func(io *ioC0Page) uint8
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type softSwitchW func(io *ioC0Page, value uint8)
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// KeyboardProvider declares the keyboard implementation requirements
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type KeyboardProvider interface {
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GetKey(strobe bool) (key uint8, ok bool)
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}
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// SpeakerProvider declares the speaker implementation requirements
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type SpeakerProvider interface {
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// Click receives a speaker click. The argument is the CPU cycle when it is generated
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Click(cycle uint64)
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}
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// See https://www.kreativekorp.com/miscpages/a2info/iomemory.shtml
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// See https://stason.org/TULARC/pc/apple2/programmer/004-I-d-like-to-do-some-serious-Apple-II-programming-Whe.html
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const (
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ssOn uint8 = 0x80
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ssOff uint8 = 0x00
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)
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func newIoC0Page(a *Apple2) *ioC0Page {
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var io ioC0Page
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io.apple2 = a
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addApple2SoftSwitches(&io)
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if a.isApple2e {
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addApple2ESoftSwitches(&io)
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}
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return &io
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}
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func (p *ioC0Page) save(w io.Writer) {
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binary.Write(w, binary.BigEndian, p.softSwitchesData)
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}
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func (p *ioC0Page) load(r io.Reader) {
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binary.Read(r, binary.BigEndian, &p.softSwitchesData)
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}
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func (p *ioC0Page) addSoftSwitchRW(address uint8, ss softSwitchR) {
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p.addSoftSwitchR(address, ss)
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p.addSoftSwitchW(address, func(p *ioC0Page, _ uint8) {
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ss(p)
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})
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}
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func (p *ioC0Page) addSoftSwitchR(address uint8, ss softSwitchR) {
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if p.softSwitchesR[address] != nil {
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fmt.Printf("Addresss 0x0c%02x is already assigned for read", address)
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}
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p.softSwitchesR[address] = ss
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}
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func (p *ioC0Page) addSoftSwitchW(address uint8, ss softSwitchW) {
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if p.softSwitchesW[address] != nil {
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fmt.Printf("Addresss 0x0c%02x is already assigned for write", address)
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}
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p.softSwitchesW[address] = ss
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}
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func (p *ioC0Page) isSoftSwitchActive(ioFlag uint8) bool {
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return (p.softSwitchesData[ioFlag] & ssOn) == ssOn
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}
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func (p *ioC0Page) setKeyboardProvider(kb KeyboardProvider) {
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p.keyboard = kb
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}
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func (p *ioC0Page) setSpeakerProvider(s SpeakerProvider) {
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p.speaker = s
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}
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func (p *ioC0Page) peek(address uint16) uint8 {
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//fmt.Printf("Peek on $%02x\n", address)
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pageAddress := uint8(address)
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ss := p.softSwitchesR[pageAddress]
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if ss == nil {
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if p.apple2.panicSS {
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panic(fmt.Sprintf("Unknown softswitch on read to 0xC0%02x", pageAddress))
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}
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return 0
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}
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return ss(p)
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}
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func (p *ioC0Page) poke(address uint16, value uint8) {
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//fmt.Printf("Poke on $%02x with %02x\n", address, value)
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pageAddress := uint8(address)
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ss := p.softSwitchesW[pageAddress]
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if ss == nil {
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if p.apple2.panicSS {
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panic(fmt.Sprintf("Unknown softswitch on write to 0xC0%02x", pageAddress))
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}
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return
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}
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ss(p, value)
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}
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