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Use symbolic names instead of numbers

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git-svn-id: svn://svn.cc65.org/cc65/trunk@2457 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2003-09-28 21:39:20 +00:00
parent b9e15ea410
commit 873d9adde9
1 changed files with 34 additions and 41 deletions
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75
libsrc/c64/c64-ptvjoy.s
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@ -84,14 +84,12 @@ COUNT:
; READ: Read a particular joystick passed in A.
;
READ:
tax ; Joystick number into X
bne joy2
READ: tax ; Joystick number into X
bne joy2
; Read joystick 1
; Read joystick 1
joy1:
lda #$7F
joy1: lda #$7F
sei
sta CIA1_PRA
lda CIA1_PRB
@ -100,58 +98,53 @@ joy1:
eor #$1F
rts
; Read joystick 2
; Read joystick 2
joy2:
dex
bne joy3
joy2: dex
bne joy3
; ldx #0
lda #$E0
ldy #$FF
lda #$E0
ldy #$FF
sei
sta CIA1_DDRA
lda CIA1_PRA
sty CIA1_DDRA
sta CIA1_DDRA
lda CIA1_PRA
sty CIA1_DDRA
cli
and #$1F
eor #$1F
and #$1F
eor #$1F
rts
; Read joystick 3
; Read joystick 3
joy3:
dex
bne joy4
joy3: dex
bne joy4
lda #%10000000 ; cia 2 port B Data-Direction
sta $dd03 ; bit 7: out bit 6-0: in
lda #%10000000 ; cia 2 port B Data-Direction
sta CIA2_DDRB ; bit 7: out bit 6-0: in
lda #$80 ; cia 2 port B read/write
sta $dd01 ; (output one at PB7)
lda #$80 ; cia 2 port B read/write
sta CIA2_PRB ; (output one at PB7)
lda $dd01 ; cia 2 port B read/write
and #$1f ; get bit 4-0 (PB4-PB0)
; ldx #0
lda CIA2_PRB ; cia 2 port B read/write
and #$1f ; get bit 4-0 (PB4-PB0)
rts
; Read joystick 4
; Read joystick 4
joy4:
lda #%10000000 ; cia 2 port B Data-Direction
sta $dd03 ; bit 7: out bit 6-0: in
joy4: lda #%10000000 ; cia 2 port B Data-Direction
sta CIA2_DDRB ; bit 7: out bit 6-0: in
lda #$00 ; cia 2 port B read/write
sta $dd01 ; (output zero at PB7)
lda #$00 ; cia 2 port B read/write
sta CIA2_PRB ; (output zero at PB7)
lda $dd01 ; cia 2 port B read/write
and #$0f ; get bit 3-0 (PB3-PB0)
sta tmp1 ; joy 4 directions
lda CIA2_PRB ; cia 2 port B read/write
and #$0f ; get bit 3-0 (PB3-PB0)
sta tmp1 ; joy 4 directions
lda $dd01 ; cia 2 port B read/write
and #%00100000 ; get bit 5 (PB5)
lda CIA2_PRB ; cia 2 port B read/write
and #%00100000 ; get bit 5 (PB5)
lsr
ora tmp1
ora tmp1
ldx #0
rts