4cade/src/demo/space.eggs.a

67 lines
1.4 KiB
Plaintext

;license:MIT
;(c) 2021 by Frank M.
!cpu 6502
!to "res/DEMO/SPACE.EGGS",plain
*=$300
!source "src/constants.a" ; no code in these
!source "src/macros.a"
+GAME_REQUIRES_JOYSTICK
+READ_RAM2_WRITE_RAM2
jsr EnableAccelerator
+LOAD_FILE_AT title, $00
+NEW_RESET_VECTOR $280
lda #$60
sta $2056
jsr $2000 ; decompress
lda #$EA
sta $4821
sta $4821+1
sta $4821+2
sta $4821+3
sta $4821+4
sta $4821+5 ; avoid clobbering stack
lda #$AD
sta $4B00
lda #0
sta $4B00+1
lda #$C0
sta $4B00+2 ; change button press detection to keypress detection
lda #$4C
sta $4B06
lda #0
sta $4B06+1
lda #1
sta $4B06+2 ; exit on keypress
ldx #11-1
- lda patch, x
sta $4BD6, x
dex
bpl - ; decrement custom counter after demo cycle and eventually exit
lda #$02
sta $4BFF ; initialize custom counter
+DISABLE_ACCEL
jmp $4880
patch !byte $CE,$FF,$4B,$10,$03,$4C,$00,$01,$4C,$B0,$4B
title !byte x_e-x_b
x_b !text "X/SPACE.EGGS/SPACE.EGGS"
x_e
!if * > $3F0 {
!error "code is too large, ends at ", *
}