6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-12-22 12:30:41 +00:00
Code Issues Projects Releases Wiki Activity

tweak driver to no more use IRQ

Browse Source
This commit is contained in:
mrdudz 2018-03-07 00:20:42 +01:00
parent 38fedfd78b
commit 3afbed48e0
1 changed files with 24 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
libsrc/c64/joy/c64-hitjoy.s
View File

@ -73,13 +73,22 @@ UNINSTALL:
rts
; ------------------------------------------------------------------------
; IRQ entry point. Is called from the C layer as a subroutine in the
; interrupt. The routine MUST return carry set if the interrupt has been
; 'handled' - which means that the interrupt source is gone. Otherwise it
; MUST return carry clear.
; COUNT: Return the total number of available joysticks in a/x.
;
IRQ: ; cia 2 setup
COUNT: lda #<JOY_COUNT
ldx #>JOY_COUNT
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
readadapter:
sei
; cia 2 setup
ldy #$00 ; port b direction
sty $dd03 ; => input
@ -143,32 +152,24 @@ IRQ: ; cia 2 setup
sta temp4
fire:
; Default Value: $40/64 on PAL
; $42/66 on NTSC
; FIXME: to be really 100% correct this should restore the correct timer
; values for the respective machine (PAL: $4025, NTSC: $4295)
; however, this should hardly be a problem in a real world program
lda #$41
sta $dc05
; Default Value: $25/37 on PAL
; $95/149 on NTSC
lda #0
sta $dc04
; We do never "handle" the interrupt, we use it just as a timer.
clc
cli
rts
; ------------------------------------------------------------------------
; COUNT: Return the total number of available joysticks in a/x.
;
READ:
pha
jsr readadapter
pla
COUNT: lda #<JOY_COUNT
ldx #>JOY_COUNT
rts
; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A.
;
READ: tax ; Joystick number into X
tax ; Joystick number into X
bne joy2
; Read joystick 1
@ -214,4 +215,3 @@ joy4: lda temp4
eor #$1F
ldx #0
rts