Support for the Softcard Z80 card and CP/M

README.md

@@ -38,6 +38,7 @@ Portable emulator of an Apple II+ or //e. Written in Go.
   - MultiROM card
   - Dan ][ Controller card
   - ProDOS ROM card
+  - Microsoft Z80 Softcard using the [Z80](https://github.com/koron-go/z80) emulation from Koron
 - Useful cards not emulating a real card
   - Bootable SmartPort / ProDOS card with the following smartport devices:
       - Block device (hard disks)
@@ -230,6 +231,7 @@ The available pre-configured models are:
   2plus: Apple ][+
   base64a: Base 64A
   basis108: Basis 108
+  cpm: Apple ][+ with CP/M
   dos32: Apple ][ with 13 sectors disk adapter and DOS 3.2x
   swyft: swyft
 
@@ -256,6 +258,7 @@ The available cards are:
   thunderclock: Clock card
   videx: Videx compatible 80 columns card
   vidhd: Firmware signature of the VidHD card to trick Total Replay to use the SHR mode
+  z80softcard: Microsoft Z80 SoftCard to run CP/M
 
 The available tracers are:
   cpm65: Trace CPM65 BDOS calls

cardBuilder.go

@@ -61,6 +61,7 @@ func getCardFactory() map[string]*cardBuilder {
 	cardFactory["thunderclock"] = newCardThunderClockPlusBuilder()
 	cardFactory["videx"] = newCardVidexBuilder()
 	cardFactory["vidhd"] = newCardVidHDBuilder()
+	cardFactory["z80softcard"] = newCardZ80SoftCardBuilder()
 	return cardFactory
 }
 

cardZ80Softcard.go

@@ -0,0 +1,117 @@
+package izapple2
+
+import (
+	"fmt"
+
+	"github.com/koron-go/z80"
+)
+
+/*
+
+Microsoft Z80 SoftCard
+See:
+	http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Z80%20Cards/Microsoft%20SoftCard/
+
+
+This card activates DMA to take control of the system. DMA is actiavted or
+deactivated by writing to the Csxx area.
+
+The emulation works on the Apple II+, but doesn't work when 80 columns are
+available. It is not working then on the Apple IIe or the Apple II+ with a
+Videx card.
+
+
+*/
+
+// CardVidHD represents a VidHD card
+type CardZ80SoftCard struct {
+	cardBase
+
+	cpu       *z80.CPU
+	z80Active bool
+}
+
+func newCardZ80SoftCardBuilder() *cardBuilder {
+	return &cardBuilder{
+		name:        "Microsoft Z80 SoftCard",
+		description: "Microsoft Z80 SoftCard to run CP/M",
+		buildFunc: func(params map[string]string) (Card, error) {
+			var c CardZ80SoftCard
+			c.romCxxx = &cardROMWriteTrap{
+				callback: func() {
+					c.flipDMA()
+				},
+			}
+
+			return &c, nil
+		},
+	}
+}
+
+func (c *CardZ80SoftCard) assign(a *Apple2, slot int) {
+	mem := &cardZ80SoftCardMMU{
+		mmu: a.mmu,
+	}
+
+	c.cpu = &z80.CPU{
+		Memory: mem,
+	}
+
+	c.cardBase.assign(a, slot)
+}
+
+func (c *CardZ80SoftCard) flipDMA() {
+	c.tracef("Z80 DMA flip\n")
+	c.z80Active = !c.z80Active
+	if c.z80Active {
+		c.activateDMA()
+	} else {
+		c.deactivateDMA()
+	}
+}
+
+func (c *CardZ80SoftCard) runDMACycle() {
+	if c.a.cpuTrace {
+		fmt.Printf("Z80 pc=$%04x ($%04x for the 6502) Opcode: $%02x \n",
+			c.cpu.PC, z80AddressTranslation(c.cpu.PC), c.cpu.Memory.Get(c.cpu.PC))
+	}
+	c.cpu.Step()
+}
+
+type cardROMWriteTrap struct {
+	callback func()
+}
+
+func (r *cardROMWriteTrap) peek(address uint16) uint8 {
+	return 0
+}
+
+func (r *cardROMWriteTrap) poke(address uint16, value uint8) {
+	if address >= 0xC000 && address < 0xC800 {
+		r.callback()
+	}
+}
+
+type cardZ80SoftCardMMU struct {
+	mmu *memoryManager
+}
+
+func (m *cardZ80SoftCardMMU) Get(addr uint16) uint8 {
+	return m.mmu.Peek(z80AddressTranslation(addr))
+}
+
+func (m *cardZ80SoftCardMMU) Set(addr uint16, value uint8) {
+	m.mmu.Poke(z80AddressTranslation(addr), value)
+}
+
+func z80AddressTranslation(addr uint16) uint16 {
+	if addr < 0xb000 {
+		return addr + 0x1000
+	} else if addr < 0xe000 {
+		return addr + 0x2000
+	} else if addr < 0xf000 {
+		return addr - 0x2000
+	} else {
+		return addr - 0xf000
+	}
+}

cardZ80softcard_test.go

@@ -0,0 +1,28 @@
+package izapple2
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestCPMBoot(t *testing.T) {
+	at, err := makeApple2Tester("cpm", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	banner := "APPLE ][ CP/M"
+	prompt := "A>"
+	at.terminateCondition = buildTerminateConditionTexts([]string{banner, prompt}, testTextMode40, 10_000_000)
+
+	at.run()
+
+	text := at.getText(testTextMode40)
+	if !strings.Contains(text, banner) {
+		t.Errorf("Expected '%s', got '%s'", banner, text)
+	}
+	if !strings.Contains(text, prompt) {
+		t.Errorf("Expected prompt '%s', got '%s'", prompt, text)
+	}
+
+}

configs/cpm.cfg

@@ -0,0 +1,6 @@
+name: Apple ][+ with CP/M
+parent: 2plus
+# Fails with 80 columns
+s3: empty
+s4: z80softcard
+s6: diskii,disk1=<internal>/cpm_2.20B_56K.po

doc/usage.txt

@@ -51,6 +51,7 @@ The available pre-configured models are:
   2plus: Apple ][+
   base64a: Base 64A
   basis108: Basis 108
+  cpm: Apple ][+ with CP/M
   dos32: Apple ][ with 13 sectors disk adapter and DOS 3.2x
   swyft: swyft
 
@@ -77,6 +78,7 @@ The available cards are:
   thunderclock: Clock card
   videx: Videx compatible 80 columns card
   vidhd: Firmware signature of the VidHD card to trick Total Replay to use the SHR mode
+  z80softcard: Microsoft Z80 SoftCard to run CP/M
 
 The available tracers are:
   cpm65: Trace CPM65 BDOS calls

go.mod

@@ -6,6 +6,7 @@ require (
 	fyne.io/fyne/v2 v2.1.4
 	github.com/go-gl/glfw/v3.3/glfw v0.0.0-20240118000515-a250818d05e3
 	github.com/ivanizag/iz6502 v1.4.0
+	github.com/koron-go/z80 v0.10.1
 	github.com/pkg/profile v1.7.0
 	github.com/veandco/go-sdl2 v0.4.38
 	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a

go.sum

@@ -42,6 +42,8 @@ github.com/ivanizag/iz6502 v1.4.0 h1:7eYygUkCPwFRH0tf2JSg1k+Sy27wwPi3ActuVNVv1Uc
 github.com/ivanizag/iz6502 v1.4.0/go.mod h1:h4gbw3IK6WCYawi00kBhQ4ACeQkGWgqbUeAgDaQpy6s=
 github.com/jackmordaunt/icns v0.0.0-20181231085925-4f16af745526/go.mod h1:UQkeMHVoNcyXYq9otUupF7/h/2tmHlhrS2zw7ZVvUqc=
 github.com/josephspurrier/goversioninfo v0.0.0-20200309025242-14b0ab84c6ca/go.mod h1:eJTEwMjXb7kZ633hO3Ln9mBUCOjX2+FlTljvpl9SYdE=
+github.com/koron-go/z80 v0.10.1 h1:Jfb0esP/QFL4cvcr+eFECVG0Y/mA9JBLC4EKbMU5zAY=
+github.com/koron-go/z80 v0.10.1/go.mod h1:ry+Zl9kRKelzaDG9UzEtUpUnXy0Yv/kk1YEaX958xdk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=