ROM can be paged, refactor the Base64A ROM

base64a.go

@@ -1,8 +1,6 @@
 package izapple2
 
-import (
-	"fmt"
-)
+import "fmt"
 
 /*
 	Copam BASE64A adaptation.
@@ -36,14 +34,16 @@ func loadBase64aRom(a *Apple2) error {
 		}
 	}
 
-	// Create banks
-	for j := range romBanksBytes {
-		a.mmu.physicalROM[j] = newMemoryRange(0xd000, romBanksBytes[j], fmt.Sprintf("Base64 ROM page %v", j))
+	// Create paged ROM
+	romData := make([]uint8, 0, base64aRomBankSize*base64aRomBankCount)
+	for _, bank := range romBanksBytes {
+		romData = append(romData, bank...)
 	}
+	rom := newMemoryRangePagedROM(0xd000, romData, "Base64 ROM", base64aRomBankCount)
 
 	// Start with first bank active
-	a.mmu.setActiveROMPage(0)
-
+	rom.setPage(0)
+	a.mmu.physicalROM = rom
 	return nil
 }
 
@@ -55,23 +55,31 @@ func addBase64aSoftSwitches(io *ioC0Page) {
 	// ROM pagination softswitches. They use the annunciator 0 and 1
 	mmu := io.apple2.mmu
 	io.addSoftSwitchRW(0x58, func() uint8 {
-		p := mmu.getActiveROMPage()
-		mmu.setActiveROMPage(p & 2)
+		if rom, ok := mmu.physicalROM.(*memoryRangeROM); ok {
+			p := rom.getPage()
+			rom.setPage(p & 2)
+		}
 		return 0
 	}, "ANN0OFF-ROM")
 	io.addSoftSwitchRW(0x59, func() uint8 {
-		p := mmu.getActiveROMPage()
-		mmu.setActiveROMPage(p | 1)
+		if rom, ok := mmu.physicalROM.(*memoryRangeROM); ok {
+			p := rom.getPage()
+			rom.setPage(p | 1)
+		}
 		return 0
 	}, "ANN0ON-ROM")
 	io.addSoftSwitchRW(0x5A, func() uint8 {
-		p := mmu.getActiveROMPage()
-		mmu.setActiveROMPage(p & 1)
+		if rom, ok := mmu.physicalROM.(*memoryRangeROM); ok {
+			p := rom.getPage()
+			rom.setPage(p & 1)
+		}
 		return 0
 	}, "ANN1OFF-ROM")
 	io.addSoftSwitchRW(0x5B, func() uint8 {
-		p := mmu.getActiveROMPage()
-		mmu.setActiveROMPage(p | 2)
+		if rom, ok := mmu.physicalROM.(*memoryRangeROM); ok {
+			p := rom.getPage()
+			rom.setPage(p | 2)
+		}
 		return 0
 	}, "ANN1ON-ROM")
 

cardThunderClockPlus.go

@@ -31,9 +31,7 @@ func newCardThunderClockPlusBuilder() *cardBuilder {
 	return &cardBuilder{
 		name:          "ThunderClock+ Card",
 		description:   "Clock card",
-		defaultParams: &[]paramSpec{
-			{"rom", "ROM file to load", "<internal>/ThunderclockPlusROM.bin"},
-		},
+		defaultParams: &[]paramSpec{},
 		buildFunc: func(params map[string]string) (Card, error) {
 			var c CardThunderClockPlus
 			err := c.loadRomFromResource("<internal>/ThunderclockPlusROM.bin")

memoryManager.go

@@ -16,7 +16,7 @@ type memoryManager struct {
 	cardsROMExtra [8]memoryHandler // 0xc800 to 0xcfff. 2048 bytes for each card
 
 	// Upper area ROM: 0xc000 to 0xffff (or 0xd000 to 0xffff on the II+)
-	physicalROM [4]memoryHandler // 0xc000 (or 0xd000) to 0xffff, 16 (or 12) Kb. Up to four banks
+	physicalROM memoryHandler // 0xc000 (or 0xd000) to 0xffff, 16 (or 12) Kb. Up to four banks
 
 	// Language card upper area RAM: 0xd000 to 0xffff. One bank for regular LC cards, up to 8 with Saturn
 	physicalLangRAM    []*memoryRange // 0xd000 to 0xffff, 12KB. Up to 8 banks.
@@ -44,9 +44,6 @@ type memoryManager struct {
 	extendedRAMBlock      uint8         // Block used for entended memory for RAMWorks cards
 	mainROMinhibited      memoryHandler // Alternative ROM from 0xd000 to 0xffff provided by a card with the INH signal.
 
-	// Configuration switches, Base64A
-	romPage uint8 // Active ROM page
-
 	// Resolution cache
 	lastAddressPage    uint16 // The first byte is the page. The second is zero when the cached is valid.
 	lastAddressHandler memoryHandler
@@ -90,12 +87,12 @@ func (mmu *memoryManager) accessCArea(address uint16) memoryHandler {
 	// Internal IIe slot 3
 	if (address <= addressLimitSlots) && !mmu.slotC3ROMActive && (slot == 3) {
 		mmu.intC8ROMActive = true
-		return mmu.physicalROM[mmu.romPage]
+		return mmu.physicalROM
 	}
 
 	// Internal IIe CxROM
 	if mmu.intCxROMActive {
-		return mmu.physicalROM[mmu.romPage]
+		return mmu.physicalROM
 	}
 
 	// First slot area
@@ -114,7 +111,7 @@ func (mmu *memoryManager) accessCArea(address uint16) memoryHandler {
 
 	// Extra slot area
 	if mmu.intC8ROMActive {
-		return mmu.physicalROM[mmu.romPage]
+		return mmu.physicalROM
 	}
 	return mmu.cardsROMExtra[mmu.activeSlot]
 }
@@ -188,7 +185,7 @@ func (mmu *memoryManager) accessRead(address uint16) memoryHandler {
 	if mmu.lcActiveRead {
 		return mmu.accessUpperRAMArea(address)
 	}
-	return mmu.physicalROM[mmu.romPage]
+	return mmu.physicalROM
 }
 
 func (mmu *memoryManager) accessWrite(address uint16) memoryHandler {
@@ -221,7 +218,7 @@ func (mmu *memoryManager) accessWrite(address uint16) memoryHandler {
 	if mmu.lcActiveWrite {
 		return mmu.accessUpperRAMArea(address)
 	}
-	return mmu.physicalROM[mmu.romPage]
+	return mmu.physicalROM
 }
 
 func (mmu *memoryManager) peekWord(address uint16) uint16 {
@@ -318,14 +315,6 @@ func (mmu *memoryManager) initExtendedRAM(groups int) {
 }
 
 // Memory configuration
-func (mmu *memoryManager) setActiveROMPage(page uint8) {
-	mmu.romPage = page
-}
-
-func (mmu *memoryManager) getActiveROMPage() uint8 {
-	return mmu.romPage
-}
-
 func (mmu *memoryManager) setLanguageRAM(readActive bool, writeActive bool, altBank bool) {
 	mmu.lcActiveRead = readActive
 	mmu.lcActiveWrite = writeActive

memoryRange.go

@@ -12,6 +12,8 @@ type memoryRange struct {
 
 type memoryRangeROM struct {
 	memoryRange
+	pageOffset uint16
+	pages      uint8
 }
 
 func newMemoryRange(base uint16, data []uint8, name string) *memoryRange {
@@ -25,10 +27,15 @@ func newMemoryRange(base uint16, data []uint8, name string) *memoryRange {
 }
 
 func newMemoryRangeROM(base uint16, data []uint8, name string) *memoryRangeROM {
+	return newMemoryRangePagedROM(base, data, name, 1)
+}
+
+func newMemoryRangePagedROM(base uint16, data []uint8, name string, pages uint8) *memoryRangeROM {
 	var m memoryRangeROM
 	m.base = base
 	m.data = data
 	m.name = name
+	m.pages = pages
 	return &m
 }
 
@@ -48,10 +55,27 @@ func (m *memoryRange) subRange(a, b uint16) []uint8 {
 	return m.data[a-m.base : b-m.base]
 }
 
+func (m *memoryRangeROM) setPage(page uint8) {
+	pageSize := len(m.data) / int(m.pages)
+	m.pageOffset = uint16(int(page%m.pages) * pageSize)
+}
+
+func (m *memoryRangeROM) getPage() uint8 {
+	pageSize := len(m.data) / int(m.pages)
+	return uint8(m.pageOffset / uint16(pageSize))
+}
+
+func (m *memoryRangeROM) peek(address uint16) uint8 {
+	return m.data[address-m.base+m.pageOffset]
+}
 func (m *memoryRangeROM) poke(address uint16, value uint8) {
 	// Ignore
 }
 
+func (m *memoryRangeROM) subRange(a, b uint16) []uint8 {
+	return m.data[a-m.base+m.pageOffset : b-m.base+m.pageOffset]
+}
+
 //lint:ignore U1000 this is used to write debug code
 func identifyMemory(m memoryHandler) string {
 	ram, ok := m.(*memoryRange)

noSlotClockDS1216.go

@@ -204,8 +204,8 @@ func (nsc *noSlotClockDS1216) loadTime() {
 
 func setupNoSlotClock(a *Apple2, arg string) error {
 	if arg == "main" {
-		nsc := newNoSlotClockDS1216(a, a.mmu.physicalROM[0])
-		a.mmu.physicalROM[0] = nsc
+		nsc := newNoSlotClockDS1216(a, a.mmu.physicalROM)
+		a.mmu.physicalROM = nsc
 	} else {
 		slot, err := strconv.ParseUint(arg, 10, 8)
 		if err != nil || slot < 1 || slot > 7 {

setup.go

@@ -150,7 +150,7 @@ func (a *Apple2) loadRom(filename string) error {
 	size := len(data)
 
 	romBase := 0x10000 - size
-	a.mmu.physicalROM[0] = newMemoryRangeROM(uint16(romBase), data, "Main ROM")
+	a.mmu.physicalROM = newMemoryRangeROM(uint16(romBase), data, "Main ROM")
 	return nil
 }