the10thwiz/cc65
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cleanup/fix pce cpeekc/cpeekcolor/cpeekrevers/cpeeks, replaces #532

Browse Source
This commit is contained in:
mrdudz
2025-05-25 02:52:03 +02:00
parent 5c72deb0b9
commit e9a15af29b
4 changed files with 25 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
libsrc/pce/cpeekc.s
View File

@@ -14,11 +14,11 @@ _cpeekc:
st0 #VDC_MARR ; Memory-Address Read
ldy SCREEN_PTR
ldx SCREEN_PTR+1
sty VDC_DATA_LO
stx VDC_DATA_HI
sty a:VDC_DATA_LO
stx a:VDC_DATA_HI
st0 #VDC_VRR ; VRAM Read Register
lda VDC_DATA_LO ; character
lda a:VDC_DATA_LO ; character
and #<~$80 ; remove reverse bit
ldx #0
rts

6
libsrc/pce/cpeekcolor.s
View File

@@ -14,11 +14,11 @@ _cpeekcolor:
st0 #VDC_MARR ; Memory-Address Read
ldy SCREEN_PTR
ldx SCREEN_PTR+1
sty VDC_DATA_LO
stx VDC_DATA_HI
sty a:VDC_DATA_LO
stx a:VDC_DATA_HI
st0 #VDC_VRR ; VRAM Read Register
lda VDC_DATA_HI
lda a:VDC_DATA_HI
and #<~$02
lsr a
lsr a

15
libsrc/pce/cpeekrevers.s
View File

@@ -14,13 +14,14 @@ _cpeekrevers:
st0 #VDC_MARR ; Memory-Address Read
ldy SCREEN_PTR
ldx SCREEN_PTR+1
sty VDC_DATA_LO
stx VDC_DATA_HI
sty a:VDC_DATA_LO
stx a:VDC_DATA_HI
st0 #VDC_VRR ; VRAM Read Register
lda VDC_DATA_LO ; character (bit 7 is revers bit)
rol a
rol a
and #1
ldx #0
lda a:VDC_DATA_LO ; character (bit 7 is revers bit)
and #$80 ; get reverse bit
asl a ; reverse bit to carry, A=0
tax ; ldx #>$0000
rol a ; reverse bit from carry
rts

28
libsrc/pce/cpeeks.s
View File

@@ -1,5 +1,6 @@
;
; 2020-07-14, Groepaz
; 2020-07-15, Greg King
;
; void cpeeks (char* s, unsigned length);
;
@@ -8,9 +9,7 @@
.export _cpeeks
.import popax
.importzp ptr1, ptr2, tmp1, tmp2
.macpack generic
.importzp ptr1, ptr2
.include "pce.inc"
.include "extzp.inc"
@@ -22,35 +21,31 @@ _cpeeks:
eor #>$FFFF
sta ptr2+1
st0 #VDC_CR ; Control Register
st2 #>$0088 ; make VRAM address increment by one
st0 #VDC_MARR ; Memory-Address Read
ldy SCREEN_PTR
ldx SCREEN_PTR+1
sty VDC_DATA_LO
stx VDC_DATA_HI
sty a:VDC_DATA_LO
stx a:VDC_DATA_HI
st0 #VDC_VRR ; VRAM Read Register
jsr popax
sta tmp1 ; (will be a .Y index)
tay ; low byte of address will be used as index
stx ptr1+1
ldx #<$0000
stx ptr1
beq L2 ; branch always
L3: ldy tmp2
lda VDC_DATA_LO ; get character
bit VDC_DATA_HI ; we need to "read" the highbyte to advance the address
iny
sty tmp2
L3: lda a:VDC_DATA_LO ; get character
bit a:VDC_DATA_HI ; need to read high byte to advance VDC address
and #<~$80 ; remove reverse bit
ldy tmp1
sta (ptr1),y
iny
bne L1
bne L2
inc ptr1+1
L1: sty tmp1
L2: inc ptr2 ; count length
bne L3
@@ -58,6 +53,5 @@ L2: inc ptr2 ; count length
bne L3
txa ; terminate the string
ldy tmp1
sta (ptr1),y
rts