6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2025-02-04 13:32:54 +00:00
Code Issues Projects Releases Wiki Activity

Use symbolic names instead of numbers

Browse Source 
git-svn-id: svn://svn.cc65.org/cc65/trunk@2457 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2003-09-28 21:39:20 +00:00
parent b9e15ea410
commit 873d9adde9
1 changed files with 34 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
libsrc/c64/c64-ptvjoy.s
View File

@ -84,14 +84,12 @@ COUNT:
; READ: Read a particular joystick passed in A. ; READ: Read a particular joystick passed in A.
; ;
READ: READ: tax ; Joystick number into X
tax ; Joystick number into X bne joy2
bne joy2
; Read joystick 1 ; Read joystick 1
joy1: joy1: lda #$7F
lda #$7F
sei sei
sta CIA1_PRA sta CIA1_PRA
lda CIA1_PRB lda CIA1_PRB
@ -100,58 +98,53 @@ joy1:
eor #$1F eor #$1F
rts rts
; Read joystick 2 ; Read joystick 2
joy2: joy2: dex
dex bne joy3
bne joy3
; ldx #0 lda #$E0
lda #$E0 ldy #$FF
ldy #$FF
sei sei
sta CIA1_DDRA sta CIA1_DDRA
lda CIA1_PRA lda CIA1_PRA
sty CIA1_DDRA sty CIA1_DDRA
cli cli
and #$1F and #$1F
eor #$1F eor #$1F
rts rts
; Read joystick 3 ; Read joystick 3
joy3: joy3: dex
dex bne joy4
bne joy4
lda #%10000000 ; cia 2 port B Data-Direction lda #%10000000 ; cia 2 port B Data-Direction
sta $dd03 ; bit 7: out bit 6-0: in sta CIA2_DDRB ; bit 7: out bit 6-0: in
lda #$80 ; cia 2 port B read/write lda #$80 ; cia 2 port B read/write
sta $dd01 ; (output one at PB7) sta CIA2_PRB ; (output one at PB7)
lda $dd01 ; cia 2 port B read/write lda CIA2_PRB ; cia 2 port B read/write
and #$1f ; get bit 4-0 (PB4-PB0) and #$1f ; get bit 4-0 (PB4-PB0)
; ldx #0
rts rts
; Read joystick 4 ; Read joystick 4
joy4: joy4: lda #%10000000 ; cia 2 port B Data-Direction
lda #%10000000 ; cia 2 port B Data-Direction sta CIA2_DDRB ; bit 7: out bit 6-0: in
sta $dd03 ; bit 7: out bit 6-0: in
lda #$00 ; cia 2 port B read/write lda #$00 ; cia 2 port B read/write
sta $dd01 ; (output zero at PB7) sta CIA2_PRB ; (output zero at PB7)
lda $dd01 ; cia 2 port B read/write lda CIA2_PRB ; cia 2 port B read/write
and #$0f ; get bit 3-0 (PB3-PB0) and #$0f ; get bit 3-0 (PB3-PB0)
sta tmp1 ; joy 4 directions sta tmp1 ; joy 4 directions
lda $dd01 ; cia 2 port B read/write lda CIA2_PRB ; cia 2 port B read/write
and #%00100000 ; get bit 5 (PB5) and #%00100000 ; get bit 5 (PB5)
lsr lsr
ora tmp1 ora tmp1
ldx #0 ldx #0
rts rts