4cade/src/demo/apple.oids.a
2024-05-25 17:24:57 -04:00

63 lines
1.6 KiB
Plaintext

;license:MIT
;(c) 2021-2022 by Frank M., qkumba
!cpu 6502
!to "build/DEMO/AO#06B900",plain
*=$B900
!source "src/constants.a" ; no code in these
!source "src/macros.a"
+GAME_REQUIRES_JOYSTICK
+ENABLE_ACCEL_LC
+LOAD_XSINGLE title
lda #$60
sta $604E
jsr $6000 ; decompress
lda #$4C
sta $4FD7 ; exit on keypress
sta $4F96 ; exit at end of demo
ldx #0
stx $4FD7+1
inx
stx $4FD7+2
; doesn't try to detect joystick or joystick buttons
lda #$D0 ; disable sounds
sta $0DA0 ; A-P-P-L-E-O-I-D-S
sta $1118 ; alien
sta $111F ; alien
lda #<callback
sta $4F96+1
lda #>callback
sta $4F96+2 ; wait 10 seconds at end of demo once Twilight logo is shown
+DISABLE_ACCEL
jmp $4D00
callback lda $C000
bmi +
lda #$FF
jsr $FCA8 ; WAIT 0.16395694 seconds
dec count
bne callback
+ jmp $100
count !byte $3D ; number of 0.16395694 second WAIT cycles
; (A*A*2.5 + A*13.5 + 7) * 0.980 usec
; 163,840 + 3,456 + 7 = 167,303 * 0.980 usec = 163,956.94 usec
; 163,956.94 usec = 0.16395694 seconds
; 61 cycles (hex $3D) of A=256 WAIT = 10 seconds
title +PSTRING "AO"
!if * > $BDFF {
!error "code is too large, ends at ", *
}