mirror of
https://github.com/tjboldt/Apple2-IO-RPi.git
synced 2024-10-31 14:08:27 +00:00
Revert "Avoid unwanted i/o access."
Neither the original hardware type nor the alternative hardware type have any read and write i/o port share addresses. Therefore phantom reads aren't an issue with those hardware types.
This reverts commit ae5cb754fb
.
This commit is contained in:
parent
b3acd5b312
commit
40aba1d7b6
@ -17,15 +17,10 @@ XLEN = $BE52 ;length of command string-1.
|
||||
XCNUM = $BE53 ;CI cmd no. (ext cmd - 0).
|
||||
PBITS = $BE54 ;Command parameter bits.
|
||||
XRETURN = $FF58 ;Known RTS instruction.
|
||||
|
||||
; have 6502 absolute indexed access phantom reads
|
||||
; happen on page $bf to avoid unwanted i/o access
|
||||
IndexOffset = $8f
|
||||
|
||||
InputByte = $c08e - IndexOffset
|
||||
OutputByte = $c08d - IndexOffset
|
||||
InputFlags = $c08b - IndexOffset
|
||||
OutputFlags = $c087 - IndexOffset
|
||||
InputByte = $c08e
|
||||
OutputByte = $c08d
|
||||
InputFlags = $c08b
|
||||
OutputFlags = $c087
|
||||
|
||||
ReadBlockCommand = $01
|
||||
WriteBlockCommand = $02
|
||||
@ -81,10 +76,9 @@ DetectSlot:
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
clc
|
||||
adc #IndexOffset
|
||||
tax
|
||||
bcc Start ;always
|
||||
clc
|
||||
bcc Start
|
||||
nextSlot:
|
||||
dex
|
||||
bne DetectSlot
|
||||
|
@ -19,14 +19,10 @@ IOError = $27
|
||||
NoDevice = $28
|
||||
WriteProtect = $2B
|
||||
|
||||
; have 6502 absolute indexed access phantom reads
|
||||
; happen on page $bf to avoid unwanted i/o access
|
||||
IndexOffset = $8f
|
||||
|
||||
InputByte = $c08e - IndexOffset
|
||||
OutputByte = $c08d - IndexOffset
|
||||
InputFlags = $c08b - IndexOffset
|
||||
OutputFlags = $c087 - IndexOffset
|
||||
InputByte = $c08e
|
||||
OutputByte = $c08d
|
||||
InputFlags = $c08b
|
||||
OutputFlags = $c087
|
||||
|
||||
ResetCommand = $00
|
||||
ReadBlockCommand = $01
|
||||
@ -89,10 +85,9 @@ DetectSlot:
|
||||
asl
|
||||
asl
|
||||
asl
|
||||
clc
|
||||
adc #IndexOffset
|
||||
tax
|
||||
bcc Init ;always
|
||||
clc
|
||||
bcc Init
|
||||
nextSlot:
|
||||
dex
|
||||
bne DetectSlot
|
||||
|
Loading…
Reference in New Issue
Block a user