package izapple2 /* RAM card with 128Kb. It's like 8 language cards. See: http://www.applelogic.org/files/SATURN128MAN.pdf */ // CardSaturn is a Saturn128 card type CardSaturn struct { cardBase readState bool writeState uint8 altBank bool activeBlock uint8 } // NewCardSaturn creates a new CardSaturn func NewCardSaturn() *CardSaturn { var c CardSaturn c.name = "Saturn 128KB Ram Card" return &c } const ( saturnBlocks = 8 ) func (c *CardSaturn) assign(a *Apple2, slot int) { c.readState = false c.writeState = lcWriteEnabled c.altBank = true c.activeBlock = 0 a.mmu.initLanguageRAM(saturnBlocks) for i := uint8(0x0); i <= 0xf; i++ { iCopy := i c.addCardSoftSwitchR(iCopy, func(*ioC0Page) uint8 { c.ssAction(iCopy) return 0 }, "SATURNR") c.addCardSoftSwitchW(iCopy, func(*ioC0Page, uint8) { c.ssAction(iCopy) }, "SATURNW") } c.cardBase.assign(a, slot) c.applyState() } func (c *CardSaturn) ssAction(ss uint8) { switch ss { case 0: // RAM read, no writes c.altBank = false c.readState = true c.writeState = lcWriteDisabled case 1: // ROM read, RAM write c.altBank = false c.readState = false c.writeState++ case 2: // ROM read, no writes c.altBank = false c.readState = false c.writeState = lcWriteDisabled case 3: //RAM read, RAM write c.altBank = false c.readState = true c.writeState++ case 4: c.activeBlock = 0 case 5: c.activeBlock = 1 case 6: c.activeBlock = 2 case 7: c.activeBlock = 3 case 8: // RAM read, no writes c.altBank = true c.readState = true c.writeState = lcWriteDisabled case 9: // ROM read, RAM write c.altBank = true c.readState = false c.writeState++ case 10: // ROM read, no writes c.altBank = true c.readState = false c.writeState = lcWriteDisabled case 11: //RAM read, RAM write c.altBank = true c.readState = true c.writeState++ case 12: c.activeBlock = 4 case 13: c.activeBlock = 5 case 14: c.activeBlock = 6 case 15: c.activeBlock = 7 } if c.writeState > lcWriteEnabled { c.writeState = lcWriteEnabled } c.applyState() } func (c *CardSaturn) applyState() { c.a.mmu.setLanguageRAMActiveBlock(c.activeBlock) c.a.mmu.setLanguageRAM(c.readState, c.writeState == lcWriteEnabled, c.altBank) }