mirror of
https://github.com/ivanizag/izapple2.git
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101 lines
2.3 KiB
Go
101 lines
2.3 KiB
Go
package izapple2
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/*
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Simulates just what is needed to make Total Replay use fast mode. Can change
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from controlled speed to max speed the emulator can do.
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Note: It ends up not being useful for Total Replay as loading from HD is already
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very fast. HD blocks are loaded directly on the emulated RAM.
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Note that it doesn't intefere with the Apple IIe 80 columns in slot 3. It doesn't
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have ROM or slot specific sofswitches.
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See:
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https://github.com/a2-4am/4cade/blob/master/src/hw.accel.a
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http://www.a2heaven.com/webshop/resources/pdf_document/18/82/c.pdf
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*/
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// CardFastChip represents a
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type CardFastChip struct {
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cardBase
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unlocked bool
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unlockCounter uint8
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enabled bool
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accelerated bool
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configRegister uint8
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}
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func newCardFastChipBuilder() *cardBuilder {
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return &cardBuilder{
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name: "FASTChip IIe Card - limited",
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description: "Accelerator card for Apple IIe. Limited support.",
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buildFunc: func(params map[string]string) (Card, error) {
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return &CardFastChip{}, nil
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},
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}
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}
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const (
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fastChipUnlockToken = 0x6a
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fastChipUnlockRepeats = 4
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fastChipNormalSpeed = uint8(9)
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)
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func (c *CardFastChip) assign(a *Apple2, slot int) {
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// The softswitches are outside the card reserved ss
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// Only writes are implemented to avoid conflicts with the joysticks
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a.io.addSoftSwitchW(0x6a, func(value uint8) {
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if value == fastChipUnlockToken {
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c.unlockCounter++
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if c.unlockCounter >= fastChipUnlockRepeats {
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c.unlocked = true
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}
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} else {
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c.unlockCounter = 0
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c.unlocked = false
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c.enabled = false
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}
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}, "FASTCHIP-LOCK")
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a.io.addSoftSwitchW(0x6b, func(uint8) {
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if c.unlocked {
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c.enabled = true
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}
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}, "FASTCHIP-ENABLE")
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a.io.addSoftSwitchW(0x6d, func(value uint8) {
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if c.enabled {
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c.setSpeed(a, value)
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}
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}, "FASTCHIP-SPEED")
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a.io.addSoftSwitchW(0x6e, func(value uint8) {
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if c.enabled {
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c.configRegister = value
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}
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}, "FASTCHIP-CONFIG")
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a.io.addSoftSwitchW(0x6f, func(value uint8) {
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if c.enabled && c.configRegister == 0 {
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c.setSpeed(a, value)
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}
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}, "FASTCHIP-CONFIG")
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c.cardBase.assign(a, slot)
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}
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func (c *CardFastChip) setSpeed(a *Apple2, value uint8) {
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newAccelerated := (value > fastChipNormalSpeed)
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if newAccelerated == c.accelerated {
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// No change requested
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return
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}
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if newAccelerated {
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a.RequestFastMode()
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} else {
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a.ReleaseFastMode()
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}
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c.accelerated = newAccelerated
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}
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