6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-06-15 02:29:32 +00:00
Code Issues Projects Releases Wiki Activity

Improved reu size detection.

Browse Source
This commit is contained in:
Marco van den Heuvel 2018-03-05 15:01:55 -08:00
parent 24cfcfdd4f
commit 40e93dd931
2 changed files with 99 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
libsrc/c128/emd/c128-reu.s
View File

@ -92,17 +92,56 @@ INSTALL:
cmp REU_REUADDR ; Check for presence of REU
bne nodevice
ldy #>(128*4) ; Assume 128KB
lda REU_STATUS
and #$10 ; Check size bit
beq @L1
ldy #>(256*4) ; 256KB when size bit is set
@L1: sty pagecount+1
; determine the size
php
sei
ldy #$FF
sty curpage
sty curpage+1 ; Invalidate the current page
txa ; X = A = EM_ERR_OK
loop:
sty window
jsr reu_size_check_common
ldx #%10110000
stx REU_COMMAND
dey
cpy #$FF
bne loop
iny
size_loop:
jsr reu_size_check_common
ldx #%10110001
stx REU_COMMAND
cpy window
bne size_found
iny
bne size_loop
size_found:
plp
ldx #$00
cpy #$00 ; too many pages, shave off 2
bne pagecount_ok
dex
dex
dey
pagecount_ok:
stx pagecount
sty pagecount+1
lda #<EM_ERR_OK
ldx #>EM_ERR_OK
rts
; common REU setup for size check
reu_size_check_common:
sty REU_REUADDR+2
ldx #<window
stx REU_C64ADDR
ldx #>window
stx REU_C64ADDR+1
ldx #$00
stx REU_REUADDR
stx REU_REUADDR+1
stx REU_COUNT+1
stx REU_CONTROL
inx
stx REU_COUNT
rts
; No REU found

60
libsrc/c64/emd/c64-reu.s
View File

@ -92,19 +92,59 @@ INSTALL:
cmp REU_REUADDR ; Check for presence of REU
bne nodevice
ldy #>(128*4) ; Assume 128KB
lda REU_STATUS
and #$10 ; Check size bit
beq @L1
ldy #>(256*4) ; 256KB when size bit is set
@L1: sty pagecount+1
; determine the size
php
sei
ldy #$FF
sty curpage
sty curpage+1 ; Invalidate the current page
txa ; X = A = EM_ERR_OK
loop:
sty window
jsr reu_size_check_common
ldx #%10110000
stx REU_COMMAND
dey
cpy #$FF
bne loop
iny
size_loop:
jsr reu_size_check_common
ldx #%10110001
stx REU_COMMAND
cpy window
bne size_found
iny
bne size_loop
size_found:
plp
ldx #$00
cpy #$00 ; too many pages, shave off 2
bne pagecount_ok
dex
dex
dey
pagecount_ok:
stx pagecount
sty pagecount+1
lda #<EM_ERR_OK
ldx #>EM_ERR_OK
rts
; common REU setup for size check
reu_size_check_common:
sty REU_REUADDR+2
ldx #<window
stx REU_C64ADDR
ldx #>window
stx REU_C64ADDR+1
ldx #$00
stx REU_REUADDR
stx REU_REUADDR+1
stx REU_COUNT+1
stx REU_CONTROL
inx
stx REU_COUNT
rts
; No REU found
nodevice: