mirror of
https://github.com/ivanizag/izapple2.git
synced 2024-11-10 10:07:00 +00:00
148 lines
2.5 KiB
Go
148 lines
2.5 KiB
Go
package apple2
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import (
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"fmt"
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)
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/*
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In out card experiment to interface with the emulator host.
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See:
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"Apple II Monitors peeled."
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http://mysite.du.edu/~etuttle/math/acia.htm
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*/
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type cardInOut struct {
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cardBase
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i int
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}
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func (c *cardInOut) assign(a *Apple2, slot int) {
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for i := 0x0; i <= 0xf; i++ {
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iCopy := i
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c.ssr[i] = func(*ioC0Page) uint8 {
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value := []uint8{0xc1, 0xc1, 0x93, 0x0}[c.i%4]
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c.i++
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fmt.Printf("[cardInOut] Read access to softswith 0x%x for slot %v, value %x.\n", iCopy, slot, value)
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//return 0x41 + 0x80
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return []uint8{0x41, 0x41, 0x13}[i%3] + 0x80
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}
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c.ssw[i] = func(_ *ioC0Page, value uint8) {
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fmt.Printf("[cardInOut] Write access to softswith 0x%x for slot %v, value 0x%x.\n", iCopy, slot, value)
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}
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}
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in := true
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out := false
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data := [256]uint8{
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// Register
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0xA9, 0xC2,
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0x85, 0x37,
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0x85, 0x39,
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0xA9, 0x10,
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0x85, 0x36,
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0xA9, 0x15,
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0x85, 0x38,
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0x60, 0xEA,
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// Out char
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0x8D, 0xA1, 0xC0,
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0x60, 0xEA,
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// Get char
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0x91, 0x28,
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0xAD, 0xA0, 0xC0,
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0x60,
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}
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if !out {
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// NOP the CSWL,H change
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for _, v := range []uint8{2, 3, 8, 9} {
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data[v] = 0xEA
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}
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}
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if !in {
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// NOP the KSWL,H change
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for _, v := range []uint8{4, 5, 12, 13} {
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data[v] = 0xEA
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}
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}
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c.rom = newMemoryRange(0xC200, data[0:255])
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if slot != 2 {
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// To make ifwork on other slots, patch C2, A0 and A1
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panic("Assert failed. Only slot 2 supported for the InOut card")
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}
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c.cardBase.assign(a, slot)
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}
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/*
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The ROM code was assembled using https://www.masswerk.at/6502/assembler.html
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src:
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BASL = $28
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CSWL = $36
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CSWH = $37
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KSWL = $38
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KSWH = $39
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* = $C200
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Register:
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LDA #$C2
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STA *CSWH
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STA *KSWH
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LDA #$10
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STA *CSWL
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LDA #$15
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STA *KSWL
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RTS
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NOP
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OutChar:
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STA $C0A1
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RTS
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NOP
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GetChar:
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STA (BASL),Y
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LDA $C0A0
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RTS
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assembled as:
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0000 BASL = 0028
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0000 CSWL = 0036
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0000 CSWH = 0037
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0000 KSWL = 0038
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0000 KSWH = 0039
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* = $C200
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C200 REGIST
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C200 LDA #$C2 A9 C2
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C202 STA *CSWH 85 37
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C204 STA *KSWH 85 39
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C206 LDA #$10 A9 10
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C208 STA *CSWL 85 36
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C20A LDA #$15 A9 15
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C20C STA *KSWL 85 38
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C20E RTS 60
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C20F NOP EA
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C210 OUTCHA
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C210 STA $C0A1 8D A1 C0
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C213 RTS 60
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C214 NOP EA
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C215 GETCHA
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C215 STA (BASL),Y 91 28
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C217 LDA $C0A0 AD A0 C0
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C21A RTS
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object code:
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A9 C2 85 37 85 39 A9 10
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85 36 A9 15 85 38 60 EA
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8D A1 C0 60 EA 91 28 AD
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A0 C0 60
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*/
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