/
ppi.go
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/
ppi.go
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package cpc
import (
"sync"
"github.com/laullon/b2t80s/emulator"
"github.com/laullon/b2t80s/emulator/ay8912"
"github.com/laullon/b2t80s/emulator/storage/cassette"
"github.com/veandco/go-sdl2/sdl"
)
const (
psgINACTIVE byte = 0
psgREAD byte = 1
psgWRITE byte = 2
psgSELECT byte = 3
)
type ppi struct {
crtc *crtc
cassette cassette.Cassette
keyboardRows []byte
keyboardLine byte
psg ay8912.AY8912
psgReg byte
psgControl byte
psgReg15 byte
a, b, c byte
aInput, bInput, clInput, chInput bool
soundOut []*emulator.SoundData
mux sync.Mutex
}
func newPPI(crtc *crtc, cassette cassette.Cassette, psg ay8912.AY8912) *ppi {
ppi := &ppi{
psg: psg,
crtc: crtc,
cassette: cassette,
keyboardRows: make([]byte, 0x10),
}
for idx := 0; idx < len(ppi.keyboardRows); idx++ {
ppi.keyboardRows[idx] = 0xff
}
return ppi
}
func (ppi *ppi) ReadPort(port uint16) (byte, bool) {
t := (port>>8)&0xf - 4
if t == 0x0 {
return ppi.readA(), false
} else if t == 0x1 {
return ppi.readB(), false
} else if t == 0x2 {
return ppi.readC(), false
} else {
panic(t)
}
}
func (ppi *ppi) WritePort(port uint16, data byte) {
t := (port>>8)&0xf - 4
if t == 0x0 {
ppi.writeA(data)
} else if t == 0x1 {
ppi.writeB(data)
} else if t == 0x2 {
ppi.writeC(data)
} else if t == 0x3 {
ppi.writeControl(data)
} else {
panic(t)
}
}
func (ppi *ppi) writeControl(value byte) {
if (value & 0x80) != 0 { // change PPI configuration
ppi.aInput = value&0b00010000 != 0
ppi.bInput = value&0b00000010 != 0
ppi.clInput = value&0b00000001 != 0
ppi.chInput = value&0b00001000 != 0
ppi.a = 0 // clear data for all ports
ppi.b = 0
ppi.c = 0
} else { // bit manipulation of port C data
bit := (value >> 1) & 7 // isolate bit to set
if (value & 1) == 1 {
ppi.c |= 1 << bit // set requested bit
} else {
ppi.c &= ^(1 << bit) // reset requested bit
}
if !ppi.clInput { // output lower half?
ppi.keyboardLine = ppi.c
}
if !ppi.chInput { // output upper half?
ppi.cassette.Motor(value&0x10 != 0)
ppi.psgControl = (value & 0xc0) >> 6
ppi.psgWrite(ppi.a)
}
}
}
func (ppi *ppi) writeA(value byte) {
ppi.a = value
if !ppi.aInput {
ppi.psgWrite(value)
}
}
func (ppi *ppi) writeB(value byte) {
ppi.b = value
}
func (ppi *ppi) writeC(value byte) {
ppi.c = value
if !ppi.clInput { // output lower half?
ppi.keyboardLine = value
}
if !ppi.chInput { // output upper half?
ppi.cassette.Motor(value&0x10 != 0)
ppi.psgControl = (value & 0xc0) >> 6
ppi.psgWrite(ppi.a)
}
}
func (ppi *ppi) psgWrite(data byte) {
if ppi.psgControl == psgSELECT {
ppi.psgReg = data
} else if ppi.psgControl == psgWRITE {
if ppi.psgReg < 16 {
if ppi.psgReg == 14 {
ppi.keyboardLine = data
} else {
ppi.psg.WriteRegister(ppi.psgReg, data)
}
} else {
panic(ppi.psgReg)
}
}
}
func (ppi *ppi) readA() (res byte) {
if ppi.aInput {
if ppi.psgControl == psgREAD {
if ppi.psgReg < 16 {
if ppi.psgReg == 14 {
res = ppi.keyboardRows[ppi.keyboardLine&0x0f]
} else {
res = ppi.psg.ReadRegister(ppi.psgReg)
}
} else {
panic(ppi.psgReg)
}
}
} else {
res = ppi.a
}
return res
}
func (ppi *ppi) readB() byte {
if ppi.bInput {
res := byte(0b00011110)
if ppi.crtc.status.vSync {
res |= 1
}
if ppi.cassette.Ear() {
res |= 0b10000000
}
return res
}
return ppi.b
}
func (ppi *ppi) readC() (res byte) {
res = ppi.c
if ppi.clInput || ppi.chInput { // either half set to input?
if ppi.chInput {
res &= 0x0f // blank out upper half
val := ppi.c & 0xc0 // isolate PSG control bits
if val == 0xc0 { // PSG specify register?
val = 0x80 // change to PSG write register
}
res |= val | 0x20 // casette write data is always set
if ppi.cassette.IsMotorON() {
res |= 0x10 // set the bit if the tape motor is running
}
}
if !ppi.clInput { // lower half set to output?
res |= 0x0f // invalid - set all bits
}
}
return res
}
func (ppi *ppi) OnKey(key sdl.Scancode) {
switch key {
case sdl.SCANCODE_UP:
ppi.keyboardRows[0] ^= 0b00000001
case sdl.SCANCODE_RIGHT:
ppi.keyboardRows[0] ^= 0b00000010
case sdl.SCANCODE_DOWN:
ppi.keyboardRows[0] ^= 0b00000100
case sdl.SCANCODE_F9:
ppi.keyboardRows[0] ^= 0b00001000
case sdl.SCANCODE_F6:
ppi.keyboardRows[0] ^= 0b00010000
case sdl.SCANCODE_F3:
ppi.keyboardRows[0] ^= 0b00100000
case sdl.SCANCODE_RETURN:
ppi.keyboardRows[0] ^= 0b01000000
case sdl.SCANCODE_F11:
ppi.keyboardRows[0] ^= 0b10000000
case sdl.SCANCODE_LEFT:
ppi.keyboardRows[1] ^= 0b00000001
// case sdl.SCANCODE_\U: COPY
// ppi.keyboardRows[1] ^= 0b00000010
case sdl.SCANCODE_F7:
ppi.keyboardRows[1] ^= 0b00000100
case sdl.SCANCODE_F8:
ppi.keyboardRows[1] ^= 0b00001000
case sdl.SCANCODE_F5:
ppi.keyboardRows[1] ^= 0b00010000
case sdl.SCANCODE_F1:
ppi.keyboardRows[1] ^= 0b00100000
case sdl.SCANCODE_F2:
ppi.keyboardRows[1] ^= 0b01000000
case sdl.SCANCODE_F10:
ppi.keyboardRows[1] ^= 0b10000000
// case sdl.SCANCODE_UP: CLR
// ppi.keyboardRows[2] ^= 0b00000001
case sdl.SCANCODE_LEFTBRACKET:
ppi.keyboardRows[2] ^= 0b00000010
case sdl.SCANCODE_KP_ENTER:
ppi.keyboardRows[2] ^= 0b00000100
case sdl.SCANCODE_RIGHTBRACKET:
ppi.keyboardRows[2] ^= 0b00001000
case sdl.SCANCODE_F4:
ppi.keyboardRows[2] ^= 0b00010000
case sdl.SCANCODE_LSHIFT, sdl.SCANCODE_RSHIFT:
ppi.keyboardRows[2] ^= 0b00100000
case sdl.SCANCODE_BACKSLASH:
ppi.keyboardRows[2] ^= 0b01000000
case sdl.SCANCODE_LCTRL, sdl.SCANCODE_RCTRL:
ppi.keyboardRows[2] ^= 0b10000000
// case sdl.SCANCODE_UP: ^
// ppi.keyboardRows[3] ^= 0b00000001
case sdl.SCANCODE_MINUS:
ppi.keyboardRows[3] ^= 0b00000010
case sdl.SCANCODE_APOSTROPHE:
ppi.keyboardRows[3] ^= 0b00000100
case sdl.SCANCODE_P:
ppi.keyboardRows[3] ^= 0b00001000
case sdl.SCANCODE_SEMICOLON:
ppi.keyboardRows[3] ^= 0b00010000
// case fyne.Ke: :
// ppi.keyboardRows[3] ^= 0b00100000
case sdl.SCANCODE_SLASH:
ppi.keyboardRows[3] ^= 0b01000000
case sdl.SCANCODE_PERIOD:
ppi.keyboardRows[3] ^= 0b10000000
case sdl.SCANCODE_0:
ppi.keyboardRows[4] ^= 0b00000001
case sdl.SCANCODE_9:
ppi.keyboardRows[4] ^= 0b00000010
case sdl.SCANCODE_O:
ppi.keyboardRows[4] ^= 0b00000100
case sdl.SCANCODE_I:
ppi.keyboardRows[4] ^= 0b00001000
case sdl.SCANCODE_L:
ppi.keyboardRows[4] ^= 0b00010000
case sdl.SCANCODE_K:
ppi.keyboardRows[4] ^= 0b00100000
case sdl.SCANCODE_M:
ppi.keyboardRows[4] ^= 0b01000000
case sdl.SCANCODE_COMMA:
ppi.keyboardRows[4] ^= 0b10000000
case sdl.SCANCODE_8:
ppi.keyboardRows[5] ^= 0b00000001
case sdl.SCANCODE_7:
ppi.keyboardRows[5] ^= 0b00000010
case sdl.SCANCODE_U:
ppi.keyboardRows[5] ^= 0b00000100
case sdl.SCANCODE_Y:
ppi.keyboardRows[5] ^= 0b00001000
case sdl.SCANCODE_H:
ppi.keyboardRows[5] ^= 0b00010000
case sdl.SCANCODE_J:
ppi.keyboardRows[5] ^= 0b00100000
case sdl.SCANCODE_N:
ppi.keyboardRows[5] ^= 0b01000000
case sdl.SCANCODE_SPACE:
ppi.keyboardRows[5] ^= 0b10000000
case sdl.SCANCODE_6:
ppi.keyboardRows[6] ^= 0b00000001
case sdl.SCANCODE_5:
ppi.keyboardRows[6] ^= 0b00000010
case sdl.SCANCODE_R:
ppi.keyboardRows[6] ^= 0b00000100
case sdl.SCANCODE_T:
ppi.keyboardRows[6] ^= 0b00001000
case sdl.SCANCODE_G:
ppi.keyboardRows[6] ^= 0b00010000
case sdl.SCANCODE_F:
ppi.keyboardRows[6] ^= 0b00100000
case sdl.SCANCODE_B:
ppi.keyboardRows[6] ^= 0b01000000
case sdl.SCANCODE_V:
ppi.keyboardRows[6] ^= 0b10000000
case sdl.SCANCODE_4:
ppi.keyboardRows[7] ^= 0b00000001
case sdl.SCANCODE_3:
ppi.keyboardRows[7] ^= 0b00000010
case sdl.SCANCODE_E:
ppi.keyboardRows[7] ^= 0b00000100
case sdl.SCANCODE_W:
ppi.keyboardRows[7] ^= 0b00001000
case sdl.SCANCODE_S:
ppi.keyboardRows[7] ^= 0b00010000
case sdl.SCANCODE_D:
ppi.keyboardRows[7] ^= 0b00100000
case sdl.SCANCODE_C:
ppi.keyboardRows[7] ^= 0b01000000
case sdl.SCANCODE_X:
ppi.keyboardRows[7] ^= 0b10000000
case sdl.SCANCODE_1:
ppi.keyboardRows[8] ^= 0b00000001
case sdl.SCANCODE_2:
ppi.keyboardRows[8] ^= 0b00000010
case sdl.SCANCODE_ESCAPE:
ppi.keyboardRows[8] ^= 0b00000100
case sdl.SCANCODE_Q:
ppi.keyboardRows[8] ^= 0b00001000
case sdl.SCANCODE_TAB:
ppi.keyboardRows[8] ^= 0b00010000
case sdl.SCANCODE_A:
ppi.keyboardRows[8] ^= 0b00100000
// case sdl.SCANCODE_\U: CAPSLOCK
// ppi.keyboardRows[8] ^= 0b01000000
case sdl.SCANCODE_Z:
ppi.keyboardRows[8] ^= 0b10000000
// case sdl.SCANCODE_UP: JOY1
// ppi.keyboardRows[9] ^= 0b00000001
// case sdl.SCANCODE_RIGHT:
// ppi.keyboardRows[9] ^= 0b00000010
// case sdl.SCANCODE_DOWN:
// ppi.keyboardRows[9] ^= 0b00000100
// case sdl.SCANCODE_F9:
// ppi.keyboardRows[9] ^= 0b00001000
// case sdl.SCANCODE_F6:
// ppi.keyboardRows[9] ^= 0b00010000
// case sdl.SCANCODE_F3:
// ppi.keyboardRows[9] ^= 0b00100000
// case sdl.SCANCODE_ENTER:
// ppi.keyboardRows[9] ^= 0b01000000
case sdl.SCANCODE_DELETE, sdl.SCANCODE_BACKSPACE:
ppi.keyboardRows[9] ^= 0b10000000
}
}
func (ppi *ppi) SoundTick() {
ppi.mux.Lock()
defer ppi.mux.Unlock()
v := 0.0
if ppi.cassette.Ear() {
v = 1
}
ppi.soundOut = append(ppi.soundOut, &emulator.SoundData{L: v, R: v})
}
func (ppi *ppi) GetBuffer(max int) (res []*emulator.SoundData, l int) {
ppi.mux.Lock()
defer ppi.mux.Unlock()
if len(ppi.soundOut) > max {
res = ppi.soundOut[:max]
ppi.soundOut = ppi.soundOut[max:]
l = max
} else {
res = ppi.soundOut
ppi.soundOut = nil
l = len(res)
}
return
}
func (ppi *ppi) GetChannels() []emulator.SoundChannel {
return []emulator.SoundChannel{ppi}
}