MMU and IOU reset on the Apple IIe

apple2.go

@@ -113,6 +113,16 @@ func (a *Apple2) Run() {
 	}
 }
 
+func (a *Apple2) reset() {
+	a.cpu.Reset()
+	a.mmu.reset()
+	for _, c := range a.cards {
+		if c != nil {
+			c.reset()
+		}
+	}
+}
+
 // IsPaused returns true when emulator is paused
 func (a *Apple2) IsPaused() bool {
 	return a.paused
@@ -171,7 +181,7 @@ func (a *Apple2) executeCommand(command int) {
 	case CommandToggleCPUTrace:
 		a.cpu.SetTrace(!a.cpu.GetTrace())
 	case CommandReset:
-		a.cpu.Reset()
+		a.reset()
 	}
 }
 

cardBase.go

@@ -6,6 +6,7 @@ import "github.com/ivanizag/izapple2/storage"
 type Card interface {
 	loadRom(data []uint8)
 	assign(a *Apple2, slot int)
+	reset()
 
 	GetName() string
 	GetInfo() map[string]string
@@ -33,6 +34,10 @@ func (c *cardBase) GetInfo() map[string]string {
 	return nil
 }
 
+func (c *cardBase) reset() {
+	// nothing
+}
+
 func (c *cardBase) loadRomFromResource(resource string) {
 	data, err := storage.LoadResource(resource)
 	if err != nil {

cardDisk2.go

@@ -74,6 +74,16 @@ func (c *CardDisk2) GetInfo() map[string]string {
 	return info
 }
 
+func (c *CardDisk2) reset() {
+	// UtA2e 9-12, all sowtches forced to off
+	drive := &c.drive[c.selected]
+	drive.phases = 0      // q0, q1, q2, q3
+	c.softSwitchQ4(false) // q4
+	c.selected = 0        // q5
+	c.q6 = false
+	c.q7 = false
+}
+
 func (c *CardDisk2) assign(a *Apple2, slot int) {
 	// Q1, Q2, Q3 and Q4 phase control soft switches,
 	for i := uint8(0); i < 4; i++ {
@@ -99,17 +109,11 @@ func (c *CardDisk2) assign(a *Apple2, slot int) {
 
 	// Q4, power switch
 	c.addCardSoftSwitchR(0x8, func(_ *ioC0Page) uint8 {
-		drive := &c.drive[c.selected]
-		if drive.power {
-			drive.power = false
-			c.a.releaseFastMode()
-			if drive.diskette != nil {
-				drive.diskette.PowerOff(c.a.cpu.GetCycles())
-			}
-		}
+		c.softSwitchQ4(false)
 		return c.dataLatch
 	}, "Q4DRIVEOFF")
 	c.addCardSoftSwitchR(0x9, func(_ *ioC0Page) uint8 {
+		c.softSwitchQ4(true)
 		drive := &c.drive[c.selected]
 		if !drive.power {
 			drive.power = true
@@ -145,6 +149,25 @@ func (c *CardDisk2) assign(a *Apple2, slot int) {
 	c.cardBase.assign(a, slot)
 }
 
+func (c *CardDisk2) softSwitchQ4(value bool) {
+	drive := &c.drive[c.selected]
+	if !value && drive.power {
+		// Turn off
+		drive.power = false
+		c.a.releaseFastMode()
+		if drive.diskette != nil {
+			drive.diskette.PowerOff(c.a.cpu.GetCycles())
+		}
+	} else if value && !drive.power {
+		// Turn on
+		drive.power = true
+		c.a.requestFastMode()
+		if drive.diskette != nil {
+			drive.diskette.PowerOn(c.a.cpu.GetCycles())
+		}
+	}
+}
+
 // Q6: shift/load
 // Q7: read/write
 

cardLanguage.go

@@ -49,6 +49,17 @@ const (
 	lcWriteEnabled     = 2
 )
 
+func (c *CardLanguage) reset() {
+	if c.a.isApple2e {
+		// UtA2e 1-3, 5-23
+		c.readState = false
+		c.writeState = lcWriteEnabled
+		c.altBank = true // Start on bank2
+		c.applyState()
+	}
+
+}
+
 func (c *CardLanguage) assign(a *Apple2, slot int) {
 	c.readState = false
 	c.writeState = lcWriteEnabled

memoryManager.go

@@ -304,3 +304,25 @@ func (mmu *memoryManager) setExtendedRAMActiveBlock(block uint8) {
 	}
 	mmu.extendedRAMBlock = block
 }
+
+func (mmu *memoryManager) reset() {
+	if mmu.apple2.isApple2e {
+		// MMU UtA2e 4-14, 5-22
+		mmu.altZeroPage = false
+		mmu.altMainRAMActiveRead = false
+		mmu.altMainRAMActiveWrite = false
+		mmu.store80Active = false
+		mmu.slotC3ROMActive = false
+		mmu.intCxROMActive = false
+		mmu.intC8ROMActive = false
+
+		// IOU UtaA2e 7-3
+		// "All softswitches except KEYSTROKE, TEXT and MIXED are reset
+		// when the RESET line drops low"
+		mmu.apple2.io.softSwitchesData[ioFlagSecondPage] = ssOff
+		mmu.apple2.io.softSwitchesData[ioFlagHiRes] = ssOff
+		mmu.apple2.io.softSwitchesData[ioFlag80Col] = ssOff
+		mmu.apple2.io.softSwitchesData[ioDataNewVideo] = ssOff
+		// ioFlagText ?
+	}
+}

romX.go

@@ -16,6 +16,13 @@ See:
 
 It is not enough to intercept the ROM accesses. RomX intercept the 74LS138 in
 position F12, that has access to the full 0xc000-0xf000 on the Apple II+
+
+Firmware:
+	- It first copies $D000-$DFFF to $6000 and runs there.
+
+go run *.go -rom ROMX.FIRM.dump -disk ROM\ X\ 20-10-22.dsk
+
+
 */
 
 type romX struct {