mirror of
https://github.com/freewilll/apple2-go.git
synced 2024-12-22 04:29:28 +00:00
Split IO into its own module
This commit is contained in:
Will Angenent
parent
a5acfb9140
commit
f8ca059f18
176
mmu/io.go
Normal file
176
mmu/io.go
Normal file
@ -0,0 +1,176 @@
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package mmu
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import (
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"fmt"
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"mos6502go/keyboard"
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)
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// https://mirrors.apple2.org.za/apple.cabi.net/Languages.Programming/MemoryMap.IIe.64K.128K.txt
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const (
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KEYBOARD = 0xC000 // keyboard data (latched) (RD-only)
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CLR80COL = 0xC000 // use 80-column memory mapping (WR-only)
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SET80COL = 0xC001
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CLRAUXRD = 0xC002 // read from auxilliary 48K
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SETAUXRD = 0xC003
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CLRAUXWR = 0xC004 // write to auxilliary 48K
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SETAUXWR = 0xC005
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CLRCXROM = 0xC006 // use external slot ROM
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SETCXROM = 0xC007
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CLRAUXZP = 0xC008 // use auxilliary ZP, stack, & LC
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SETAUXZP = 0xC009
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CLRC3ROM = 0xC00A // use external slot C3 ROM
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SETC3ROM = 0xC00B
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CLR80VID = 0xC00C // use 80-column display mode
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SET80VID = 0xC00D
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CLRALTCH = 0xC00E // use alternate character set ROM
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SETALTCH = 0xC00F
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STROBE = 0xC010 // strobe (unlatch) keyboard data
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RDLCBNK2 = 0xC011 // reading from LC bank $Dx 2
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RDLCRAM = 0xC012 // reading from LC RAM
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RDRAMRD = 0xC013 // reading from auxilliary 48K
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RDRAMWR = 0xC014 // writing to auxilliary 48K
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RDCXROM = 0xC015 // using external slot ROM
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RDAUXZP = 0xC016 // using auxilliary ZP, stack, & LC
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RDC3ROM = 0xC017 // using external slot C3 ROM
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RD80COL = 0xC018 // using 80-column memory mapping
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RDVBLBAR = 0xC019 // not VBL (VBL signal low)
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RDTEXT = 0xC01A // using text mode
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RDMIXED = 0xC01B // using mixed mode
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RDPAGE2 = 0xC01C // using text/graphics page2
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RDHIRES = 0xC01D // using Hi-res graphics mode
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RDALTCH = 0xC01E // using alternate character set ROM
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RD80VID = 0xC01F // using 80-column display mode
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SPEAKER = 0xC030 // toggle speaker diaphragm
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CLRTEXT = 0xC050 // enable text-only mode
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SETTEXT = 0xC051
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CLRMIXED = 0xC052 // enable graphics/text mixed mode
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SETMIXED = 0xC053
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TXTPAGE1 = 0xC054 // select page1/2 (or page1/1x)
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TXTPAGE2 = 0xC055
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CLRHIRES = 0xC056 // enable Hi-res graphics
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SETHIRES = 0xC057
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SETAN0 = 0xC058 // 4-bit annunciator inputs
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CLRAN0 = 0xC059
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SETAN1 = 0xC05A
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CLRAN1 = 0xC05B
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SETAN2 = 0xC05C
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CLRAN2 = 0xC05D
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SETAN3 = 0xC05E
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CLRAN3 = 0xC05F
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OPNAPPLE = 0xC061 // open apple (command) key data
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CLSAPPLE = 0xC062 // closed apple (option) key data
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PDLTRIG = 0xC070 // trigger paddles
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)
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// Handle soft switch addresses where both a read and a write has a side
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// effect and the return value is meaningless
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func readWrite(address uint16) bool {
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switch address {
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case CLRTEXT:
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panic("CLRTEXT not implemented")
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case SETTEXT:
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return true
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case TXTPAGE1:
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return true
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case TXTPAGE2:
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return true
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fmt.Println("TXTPAGE2 not implemented")
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// panic("TXTPAGE2 not implemented")
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return true
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case CLRHIRES:
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return true
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case SETHIRES:
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panic("SETIRES not implemented")
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default:
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return false
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}
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}
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func ReadIO(address uint16) uint8 {
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if readWrite(address) {
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return 0
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}
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switch address {
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case KEYBOARD, STROBE:
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keyBoardData, strobe := keyboard.Read()
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if address == KEYBOARD {
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return keyBoardData
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} else {
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keyboard.ResetStrobe()
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return strobe
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}
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case RDCXROM:
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if UsingExternalSlotRom {
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return 0x8d
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} else {
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return 0x0d
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}
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case RD80VID:
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// using 80-column display mode not implemented
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return 0x0d
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// 4-bit annunciator inputs
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case SETAN0, CLRAN0, SETAN1, CLRAN1, SETAN2, CLRAN2, SETAN3, CLRAN3:
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// Annunciators not implemented
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case OPNAPPLE:
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// Open apple key not implemented
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return 0
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case CLSAPPLE:
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// Closed apple key not implemented
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case RD80COL:
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// RD80COL not implemented
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return 0x0d
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case RDPAGE2:
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// RDPAGE2 not implemented
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return 0x0d
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case RDALTCH:
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// RDALTCH not implemented
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return 0x0d
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case SPEAKER:
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// Speaker not implemented
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// Not printing anything since this will generate a lot of noise
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default:
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panic(fmt.Sprintf("TODO read %04x\n", address))
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}
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return 0
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}
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func WriteIO(address uint16, value uint8) {
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if readWrite(address) {
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return
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}
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switch address {
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case STROBE:
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keyboard.ResetStrobe()
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case CLRCXROM:
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MapFirstHalfOfIO()
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case SETCXROM:
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MapSecondHalfOfIO()
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case CLRALTCH:
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return
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case SETALTCH:
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panic("SETALTCH not implemented")
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case CLR80COL:
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// CLR80COL not implemented
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return
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case SET80COL:
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// SET80COL not implemented
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case CLRC3ROM:
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// CLRC3ROM not implemented
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case SETC3ROM:
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// SETC3ROM not implemented
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default:
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panic(fmt.Sprintf("TODO write %04x\n", address))
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}
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return
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}
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91
mmu/mmu.go
91
mmu/mmu.go
@ -3,53 +3,12 @@ package mmu
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import (
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"fmt"
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"io/ioutil"
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"mos6502go/keyboard"
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"mos6502go/system"
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)
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const RomPath = "apple2e.rom"
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const StackPage = 1
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// https://mirrors.apple2.org.za/apple.cabi.net/Languages.Programming/MemoryMap.IIe.64K.128K.txt
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const (
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KEYBOARD = 0xC000 // keyboard data (latched) (RD-only)
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CLR80COL = 0xC000 // use 80-column memory mapping (WR-only)
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SET80COL = 0xC001
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CLRAUXRD = 0xC002 // read from auxilliary 48K
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SETAUXRD = 0xC003
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CLRAUXWR = 0xC004 // write to auxilliary 48K
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SETAUXWR = 0xC005
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CLRCXROM = 0xC006 // use external slot ROM
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SETCXROM = 0xC007
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CLRAUXZP = 0xC008 // use auxilliary ZP, stack, & LC
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SETAUXZP = 0xC009
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CLRC3ROM = 0xC00A // use external slot C3 ROM
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SETC3ROM = 0xC00B
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CLR80VID = 0xC00C // use 80-column display mode
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SET80VID = 0xC00D
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CLRALTCH = 0xC00E // use alternate character set ROM
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SETALTCH = 0xC00F
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STROBE = 0xC010 // strobe (unlatch) keyboard data
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RDLCBNK2 = 0xC011 // reading from LC bank $Dx 2
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RDLCRAM = 0xC012 // reading from LC RAM
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RDRAMRD = 0xC013 // reading from auxilliary 48K
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RDRAMWR = 0xC014 // writing to auxilliary 48K
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RDCXROM = 0xC015 // using external slot ROM
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RDAUXZP = 0xC016 // using auxilliary ZP, stack, & LC
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RDC3ROM = 0xC017 // using external slot C3 ROM
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RD80COL = 0xC018 // using 80-column memory mapping
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RDVBLBAR = 0xC019 // not VBL (VBL signal low)
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RDTEXT = 0xC01A // using text mode
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RDMIXED = 0xC01B // using mixed mode
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RDPAGE2 = 0xC01C // using text/graphics page2
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RDHIRES = 0xC01D // using Hi-res graphics mode
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RDALTCH = 0xC01E // using alternate character set ROM
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RD80VID = 0xC01F // using 80-column display mode
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)
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var PhysicalMemory struct {
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MainMemory [0xc000]uint8
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UpperROM [0x3000]uint8
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@ -59,13 +18,19 @@ var PhysicalMemory struct {
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var PageTable [0x100][]uint8
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var UsingExternalSlotRom bool
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func MapFirstHalfOfIO() {
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UsingExternalSlotRom = false
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for i := 0x1; i < 0x10; i++ {
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PageTable[i+0xc0] = PhysicalMemory.RomC1[i*0x100 : i*0x100+0x100]
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}
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}
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func MapSecondHalfOfIO() {
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UsingExternalSlotRom = true
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for i := 0x1; i < 0x10; i++ {
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PageTable[i+0xc0] = PhysicalMemory.RomC2[i*0x100 : i*0x100+0x100]
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}
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@ -121,36 +86,25 @@ func InitRAM() {
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PageTable[i] = PhysicalMemory.MainMemory[i*0x100 : i*0x100+0x100]
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}
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UsingExternalSlotRom = true
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return
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}
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func ReadMemory(address uint16) uint8 {
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if (address >= 0xc000) && (address < 0xc100) {
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if (address == KEYBOARD) || (address == STROBE) {
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keyBoardData, strobe := keyboard.Read()
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if address == KEYBOARD {
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return keyBoardData
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} else {
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keyboard.ResetStrobe()
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return strobe
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}
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} else if address == RDCXROM {
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// using external slot ROM not implemented
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return 0
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} else if address == RD80VID {
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// using 80-column display mode not implemented
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return 0
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}
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fmt.Printf("TODO read %04x\n", address)
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return 0
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return ReadIO(address)
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} else {
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return PageTable[address>>8][address&0xff]
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}
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return PageTable[address>>8][address&0xff]
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}
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func WriteMemory(address uint16, value uint8) {
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if (address >= 0xc000) && (address < 0xc100) {
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WriteIO(address, value)
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return
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}
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if system.RunningInterruptTests && address == 0xbffc {
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oldValue := ReadMemory(address)
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system.WriteInterruptTestOpenCollector(address, oldValue, value)
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@ -158,19 +112,6 @@ func WriteMemory(address uint16, value uint8) {
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return
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}
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if address >= 0xc000 {
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if address == STROBE {
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keyboard.ResetStrobe()
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} else if address == CLRCXROM {
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MapFirstHalfOfIO()
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} else if address == SETCXROM {
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MapSecondHalfOfIO()
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} else {
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fmt.Printf("TODO write %04x\n", address)
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}
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return
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}
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PageTable[uint8(address>>8)][uint8(address&0xff)] = value
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if system.RunningFunctionalTests && address == 0x200 {
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