izapple2/cardHardDisk.go
2020-10-03 23:38:26 +02:00

252 lines
7.8 KiB
Go

package izapple2
import "fmt"
/*
To implement a hard drive we just have to support boot from #PR7 and the PRODOS expextations.
See:
Beneath Prodos, section 6-6, 7-13 and 5-8. (http://www.apple-iigs.info/doc/fichiers/beneathprodos.pdf)
Apple IIc Technical Reference, 2nd Edition. Chapter 8. https://ia800207.us.archive.org/19/items/AppleIIcTechnicalReference2ndEd/Apple%20IIc%20Technical%20Reference%202nd%20ed.pdf
https://prodos8.com/docs/technote/21/
https://prodos8.com/docs/technote/20/
*/
type cardHardDisk struct {
cardBase
disk *blockDisk
mliParams uint16
trace bool
}
func buildHardDiskRom(slot int) []uint8 {
data := make([]uint8, 256)
ssBase := 0x80 + uint8(slot<<4)
copy(data, []uint8{
// Preamble bytes to comply with the expectation in $Cn01, 3, 5 and 7
0xa9, 0x20, // LDA #$20
0xa9, 0x00, // LDA #$00
0xa9, 0x03, // LDA #$03
0xa9, 0x00, // LDA #$00
// Boot code: SS will load block 0 in address $0800. The jump there.
// Note: after execution the first block expects $42 to $47 to have
// valid values to read block 0. At least Total Replay expects that.
0xa9, 0x01, // LDA·#$01
0x85, 0x42, // STA $42 ; Command READ(1)
0xa9, 0x00, // LDA·#$00
0x85, 0x43, // STA $43 ; Unit 0
0x85, 0x44, // STA $44 ; Dest LO($0800)
0x85, 0x46, // STA $46 ; Block LO(0)
0x85, 0x47, // STA $47 ; Block HI(0)
0xa9, 0x08, // LDA·#$08
0x85, 0x45, // STA $45 ; Dest HI($0800)
0xad, ssBase, 0xc0, // LDA $C0n1 ;Call to softswitch 0.
0xa2, uint8(slot << 4), // LDX $s7 ; Slot on hign nibble of X
0x4c, 0x01, 0x08, // JMP $801 ; Jump to loaded boot sector
})
if slot == 7 {
// It should be 0 for SmartPort, but with 0 it's not bootable with the II+ ROM
// See http://www.1000bit.it/support/manuali/apple/technotes/udsk/tn.udsk.2.html
data[0x07] = 0x3c
}
// Entrypoints and Smartport body
copy(data[0x40:], []uint8{
0x4c, 0x80, 0xc0 + uint8(slot), // JMP $cs80 ; Prodos Entrypoint
// 3 bytes later, smartport entrypoint. Uses the ProDos MLI calling convention
0x68, // PLA
0x8d, ssBase + 4, 0xc0, // STA $c0n4 ; Softswitch 4, store LO(cmdBlock)
0xa8, // TAY ; We will need it later
0x68, // PLA
0x8d, ssBase + 5, 0xc0, // STA $c0n5 ; Softswitch 5, store HI(cmdBlock)
0x48, // PHA
0x98, // TYA
0x18, // CLC
0x69, 0x03, // ADC #$03 ; Fix return address past the cmdblock
0x48, // PHA
0xad, ssBase + 3, 0xc0, // LDA $C0n3 ; Softswitch 3, execute command. Error code in reg A.
0x18, // CLC ; Clear carry for no errors.
0xF0, 0x01, // BEQ $01 ; Skips the SEC if reg A is zero
0x38, // SEC ; Set carry on errors
0x60, // RTS
})
// Prodos entrypoint body
copy(data[0x80:], []uint8{
0xad, ssBase + 0, 0xc0, // LDA $C0n0 ; Softswitch 0, execute command. Error code in reg A.
0x48, // PHA
0xae, ssBase + 1, 0xc0, // LDX $C0n1 ; Softswitch 1, LO(Blocks), STATUS needs that in reg X.
0xac, ssBase + 2, 0xc0, // LDY $C0n2 ; Softswitch 2, HI(Blocks). STATUS needs that in reg Y.
0x18, // CLC ; Clear carry for no errors.
0x68, // PLA ; Sets Z if no error
0xF0, 0x01, // BEQ $01 ; Skips the SEC if reg A is zero
0x38, // SEC ; Set carry on errors
0x60, // RTS
})
data[0xfc] = 0
data[0xfd] = 0
data[0xfe] = 3 // Status and Read. No write, no format. Single volume
data[0xff] = 0x40 // Driver entry point
return data
}
const (
proDosDeviceCommandStatus = 0
proDosDeviceCommandRead = 1
proDosDeviceCommandWrite = 2
proDosDeviceCommandFormat = 3
)
const (
proDosDeviceNoError = uint8(0)
proDosDeviceErrorIO = uint8(0x27)
proDosDeviceErrorNoDevice = uint8(0x28)
proDosDeviceErrorWriteProtected = uint8(0x2b)
)
func (c *cardHardDisk) assign(a *Apple2, slot int) {
c.addCardSoftSwitchR(0, func(*ioC0Page) uint8 {
// Prodos entry point
command := a.mmu.Peek(0x42)
unit := a.mmu.Peek(0x43)
address := uint16(a.mmu.Peek(0x44)) + uint16(a.mmu.Peek(0x45))<<8
block := uint16(a.mmu.Peek(0x46)) + uint16(a.mmu.Peek(0x47))<<8
if c.trace {
fmt.Printf("[CardHardDisk] Prodos command %v on slot %v, unit $%x, block %v to $%x.\n", command, slot, unit, block, address)
}
switch command {
case proDosDeviceCommandStatus:
return c.status(unit, address)
case proDosDeviceCommandRead:
return c.readBlock(block, address)
case proDosDeviceCommandWrite:
return c.writeBlock(block, address)
default:
// Prodos device command not supported
return proDosDeviceErrorIO
}
}, "HDCOMMAND")
c.addCardSoftSwitchR(1, func(*ioC0Page) uint8 {
// Blocks available, low byte
return uint8(c.disk.blocks)
}, "HDBLOCKSLO")
c.addCardSoftSwitchR(2, func(*ioC0Page) uint8 {
// Blocks available, high byte
return uint8(c.disk.blocks >> 8)
}, "HDBLOCKHI")
c.addCardSoftSwitchR(3, func(*ioC0Page) uint8 {
// Smart port entry point
command := c.a.mmu.Peek(c.mliParams + 1)
paramsAddress := uint16(c.a.mmu.Peek(c.mliParams+2)) + uint16(c.a.mmu.Peek(c.mliParams+3))<<8
unit := a.mmu.Peek(paramsAddress + 1)
address := uint16(a.mmu.Peek(paramsAddress+2)) + uint16(a.mmu.Peek(paramsAddress+3))<<8
block := uint16(a.mmu.Peek(paramsAddress+4)) + uint16(a.mmu.Peek(paramsAddress+5))<<8
if c.trace {
fmt.Printf("[CardHardDisk] Smart port command %v on slot %v, unit $%x, block %v to $%x.\n", command, slot, unit, block, address)
}
switch command {
case proDosDeviceCommandStatus:
return c.status(unit, address)
case proDosDeviceCommandRead:
return c.readBlock(block, address)
case proDosDeviceCommandWrite:
return c.writeBlock(block, address)
default:
// Smartport device command not supported
return proDosDeviceErrorIO
}
}, "HDSMARTPORT")
c.addCardSoftSwitchW(4, func(_ *ioC0Page, value uint8) {
c.mliParams = (c.mliParams & 0xff00) + uint16(value)
if c.trace {
fmt.Printf("[CardHardDisk] Smart port LO: 0x%x.\n", c.mliParams)
}
}, "HDSMARTPORTLO")
c.addCardSoftSwitchW(5, func(_ *ioC0Page, value uint8) {
c.mliParams = (c.mliParams & 0x00ff) + (uint16(value) << 8)
if c.trace {
fmt.Printf("[CardHardDisk] Smart port HI: 0x%x.\n", c.mliParams)
}
}, "HDSMARTPORTHI")
c.cardBase.assign(a, slot)
}
func (c *cardHardDisk) readBlock(block uint16, dest uint16) uint8 {
if c.trace {
fmt.Printf("[CardHardDisk] Read block %v into $%x.\n", block, dest)
}
data, err := c.disk.read(uint32(block))
if err != nil {
return proDosDeviceErrorIO
}
// Byte by byte transfer to memory using the full Poke code path
for i := uint16(0); i < uint16(proDosBlockSize); i++ {
c.a.mmu.Poke(dest+i, data[i])
}
return proDosDeviceNoError
}
func (c *cardHardDisk) writeBlock(block uint16, source uint16) uint8 {
if c.trace {
fmt.Printf("[CardHardDisk] Write block %v from $%x.\n", block, source)
}
if c.disk.readOnly {
return proDosDeviceErrorWriteProtected
}
// Byte by byte transfer from memory using the full Peek code path
buf := make([]uint8, proDosBlockSize)
for i := uint16(0); i < uint16(proDosBlockSize); i++ {
buf[i] = c.a.mmu.Peek(source + i)
}
err := c.disk.write(uint32(block), buf)
if err != nil {
return proDosDeviceErrorIO
}
return proDosDeviceNoError
}
func (c *cardHardDisk) status(unit uint8, dest uint16) uint8 {
if c.trace {
fmt.Printf("[CardHardDisk] Status for %v into $%x.\n", unit, dest)
}
// See http://www.1000bit.it/support/manuali/apple/technotes/smpt/tn.smpt.2.html
c.a.mmu.Poke(dest+0, 0x02) // One device
c.a.mmu.Poke(dest+1, 0xff) // No interrupt
c.a.mmu.Poke(dest+2, 0x00)
c.a.mmu.Poke(dest+3, 0x00) // Unknown manufacturer
c.a.mmu.Poke(dest+4, 0x01)
c.a.mmu.Poke(dest+5, 0x00) // Versión 1.0 final
c.a.mmu.Poke(dest+6, 0x00)
c.a.mmu.Poke(dest+7, 0x00) // Reserved
return proDosDeviceNoError
}
func (c *cardHardDisk) addDisk(disk *blockDisk) {
c.disk = disk
}
func (c *cardHardDisk) setTrace(trace bool) {
c.trace = trace
}