package apple2 /* Simulates just what is needed to make Total Replay use fast mode. Can change from controlled speed to max speed the emulator can do. Note: It ends up not being useful for Total Replay as loading from HD is already very fast. HD blocks are loaded directly on the emulated RAM. See: https://github.com/a2-4am/4cade/blob/master/src/hw.accel.a http://www.a2heaven.com/webshop/resources/pdf_document/18/82/c.pdf */ type cardFastChip struct { cardBase unlocked bool unlockCounter uint8 enabled bool accelerated bool } func buildFastChipRom() []uint8 { data := make([]uint8, 256) return data } const ( fastChipUnlockToken = 0x6a fastChipUnlockRepeats = 4 fastChipNormalSpeed = uint8(9) ) func (c *cardFastChip) assign(a *Apple2, slot int) { // The softswitches are outside the card reserved ss // Only writes are implemented to avoid conflicts with the joysticks a.io.addSoftSwitchW(0x6a, func(_ *ioC0Page, value uint8) { if value == fastChipUnlockToken { c.unlockCounter++ if c.unlockCounter >= fastChipUnlockRepeats { c.unlocked = true } } else { c.unlockCounter = 0 c.unlocked = false } }, "FASTCHIP-LOCK") a.io.addSoftSwitchW(0x6b, func(_ *ioC0Page, _ uint8) { if c.unlocked { c.enabled = true } }, "FASTCHIP-ENABLE") a.io.addSoftSwitchW(0x6d, func(_ *ioC0Page, value uint8) { if c.unlocked && c.enabled { newAccelerated := (value > fastChipNormalSpeed) if newAccelerated == c.accelerated { // No change requested return } if newAccelerated { a.requestFastMode() } else { a.releaseFastMode() } c.accelerated = newAccelerated } }, "FASTCHIP-SPEED") c.cardBase.assign(a, slot) }