dos33fsprogs/games/space_bars/keypress.s
Vince Weaver b1238af49d re-arranged the entire directory structure
this will probably upset people
2021-01-05 15:29:31 -05:00

113 lines
2.5 KiB
ArmAsm

;==========================================================
; Wait until keypressed
;==========================================================
;
wait_until_keypressed:
inc RANDOM_PTR ; randomize things a bit
lda KEYPRESS ; check if keypressed
bpl wait_until_keypressed ; if not, loop
jmp figure_out_key
;==========================================================
; Get Key
;==========================================================
;
get_key:
check_paddle_button:
; check for paddle button
bit PADDLE_BUTTON0 ; 4
bpl no_button ; 2nt/3
lda #' '+128 ; 2
jmp save_key ; 3
no_button:
lda KEYPRESS ; 3
bpl no_key ; 2nt/3
figure_out_key:
cmp #' '+128 ; the mask destroys space ; 2
beq save_key ; so handle it specially ; 2nt/3
and #$5f ; mask, to make upper-case ; 2
check_right_arrow:
cmp #$15 ; 2
bne check_left_arrow ; 2nt/3
lda #'D' ; 2
check_left_arrow:
cmp #$08 ; 2
bne check_up_arrow ; 2nt/3
lda #'A' ; 2
check_up_arrow:
cmp #$0B ; 2
bne check_down_arrow ; 2nt/3
lda #'W' ; 2
check_down_arrow:
cmp #$0A ; 2
bne check_escape ; 2nt/3
lda #'S' ; 2
check_escape:
cmp #$1B ; 2
bne save_key ; 2nt/3
lda #'Q' ; 2
jmp save_key ; 3
no_key:
bit PADDLE_STATUS ; 3
bpl no_key_store ; 2nt/3
; check for paddle action
; code from http://web.pdx.edu/~heiss/technotes/aiie/tn.aiie.06.html
inc PADDLE_STATUS ; 5
lda PADDLE_STATUS ; 3
and #$03 ; 2
beq check_paddles ; 2nt/3
jmp no_key_store ; 3
check_paddles:
lda PADDLE_STATUS ; 3
and #$80 ; 2
sta PADDLE_STATUS ; 3
ldx #$0 ; 2
LDA PTRIG ;TRIGGER PADDLES ; 4
LDY #0 ;INIT COUNTER ; 2
NOP ;COMPENSATE FOR 1ST COUNT ; 2
NOP ; 2
PREAD2: LDA PADDL0,X ;COUNT EVERY 11 uSEC. ; 4
BPL RTS2D ;BRANCH WHEN TIMED OUT ; 2nt/3
INY ;INCREMENT COUNTER ; 2
BNE PREAD2 ;CONTINUE COUNTING ; 2nt/3
DEY ;COUNTER OVERFLOWED ; 2
RTS2D: ;RETURN W/VALUE 0-255
cpy #96 ; 2
bmi paddle_left ; 2nt/3
cpy #160 ; 2
bmi no_key_store ; 2nt/3
lda #'D' ; 2
jmp save_key ; 3
paddle_left:
lda #'A' ; 2
jmp save_key ; 3
no_key_store:
lda #0 ; no key, so save a zero ; 2
save_key:
sta LASTKEY ; save the key to our buffer ; 2
bit KEYRESET ; clear the keyboard buffer ; 4
rts ; 6
;============
; 33=nokey
; 48=worstkey