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dos33fsprogs/fireworks/fireworks.s

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firework: work on background
2018-09-05 01:43:07 +00:00
; Display fancy Fireworks
; Uses the 40x48d page1/page2 every-1-scanline pageflip mode
; by deater (Vince Weaver) <vince@deater.net>
; Zero Page
FRAMEBUFFER = $00 ; $00 - $0F
YPOS = $10
YPOS_SIN = $11
CH = $24
CV = $25
GBASL = $26
GBASH = $27
BASL = $28
BASH = $29
FRAME = $60
BLARGH = $69
DRAW_PAGE = $EE
LASTKEY = $F1
PADDLE_STATUS = $F2
TEMP = $FA
WHICH = $FB
; Soft Switches
KEYPRESS= $C000
KEYRESET= $C010
SET_GR = $C050 ; Enable graphics
FULLGR = $C052 ; Full screen, no text
PAGE0 = $C054 ; Page0
PAGE1 = $C055 ; Page1
LORES = $C056 ; Enable LORES graphics
PADDLE_BUTTON0 = $C061
PADDL0 = $C064
PTRIG = $C070
; ROM routines
TEXT = $FB36 ;; Set text mode
HOME = $FC58 ;; Clear the text screen
WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
MAX = 3
lda #$ff
sta WHICH
start_over:
inc WHICH
lda WHICH
cmp #MAX
bne in_range
lda #0
sta WHICH
in_range:
;===================
; init screen
jsr TEXT
jsr HOME
bit KEYRESET
;===================
; init vars
lda #0
sta DRAW_PAGE
;=============================
; Load graphic page0
lda #$0c
sta BASH
lda #$00
sta BASL ; load image to $c00
lda WHICH
asl
asl ; which*4
tay
lda pictures,Y
sta GBASL
lda pictures+1,Y
sta GBASH
jsr load_rle_gr
lda #4
sta DRAW_PAGE
jsr gr_copy_to_current ; copy to page1
; GR part
bit PAGE1
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
jsr wait_until_keypressed
;=============================
; Load graphic page1
lda #$0c
sta BASH
lda #$00
sta BASL ; load image to $c00
lda WHICH
asl
asl ; which*4
tay
lda pictures+2,Y
sta GBASL
lda pictures+3,Y
sta GBASH
jsr load_rle_gr
lda #0
sta DRAW_PAGE
jsr gr_copy_to_current
; GR part
bit PAGE0
jsr wait_until_keypressed
;==============================
; setup graphics for vapor lock
;==============================
; Clear Page0
lda #$0
sta DRAW_PAGE
lda #$44
jsr clear_gr
; Make screen half green
lda #$11
ldy #24
jsr clear_page_loop
;=====================================================
; attempt vapor lock
; by reading the "floating bus" we can see most recently
; written value of the display
; we look for $55 (which is the grey line)
;=====================================================
; See:
; Have an Apple Split by Bob Bishop
; Softalk, October 1982
; Challenges: each scan line scans 40 bytes.
; The blanking happens at the *beginning*
; So 65 bytes are scanned, starting at adress of the line - 25
; the scan takes 8 cycles, look for 4 repeats of the value
; to avoid false positive found if the horiz blanking is mirroring
; the line (max 3 repeats in that case)
vapor_lock_loop: ; first make sure we have all zeroes
LDA #$11
zxloop:
LDX #$04
wiloop:
CMP $C051
BNE zxloop
DEX
BNE wiloop
LDA #$44 ; now look for our border color (4 times)
zloop:
LDX #$04
qloop:
CMP $C051
BNE zloop
DEX
BNE qloop
; found first line of black after green, at up to line 26 on screen
; so we want roughly 22 lines * 4 = 88*65 = 5720 + 4550 = 10270
; - 65 (for the scanline we missed) = 10205 - 12 = 10193
jsr gr_copy_to_current ; 6+ 9292
; 10193 - 9298 = 895
; Fudge factor (unknown) -30 = 865
; GR part
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
; Try X=88 Y=2 cycles=893 R2
nop
ldy #2 ; 2
loopA:
ldx #88 ; 2
loopB:
dex ; 2
bne loopB ; 2nt/3
dey ; 2
bne loopA ; 2nt/3
jmp display_loop
.align $100
;================================================
; Display Loop
;================================================
; each scan line 65 cycles
; 1 cycle each byte (40cycles) + 25 for horizontal
; Total of 12480 cycles to draw screen
; Vertical blank = 4550 cycles (70 scan lines)
; Total of 17030 cycles to get back to where was
; We want to alternate between page1 and page2 every 65 cycles
; vblank = 4550 cycles to do scrolling
; 2 + 48*( (4+2+25*(2+3)) + (4+2+23*(2+3)+4+5)) + 9)
; 48*[(6+125)-1] + [(6+115+10)-1]
display_loop:
ldy #96 ; 2
outer_loop:
bit PAGE0 ; 4
ldx #12 ; 65 cycles with PAGE0 ; 2
page0_loop: ; delay 61+bit
dex ; 2
bne page0_loop ; 2/3
; bit(4) -1(fallthrough) + loop*5 -1(fallthrouh)+4 extra = 61
; 5L = 55
bit PAGE1 ; 4
ldx #11 ; 65 cycles with PAGE1 ; 2
;
page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra)
dex ; 2
bne page1_loop ; 2/3
dey ; 2
bne outer_loop ; 2/3
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; do_nothing should be 4550+1 -2-9 -7= 4533
jsr do_nothing ; 6
lda KEYPRESS ; 4
bpl no_keypress ; 3
jmp start_over
no_keypress:
jmp display_loop ; 3
;=================================
; do nothing
;=================================
; and take 4533-6 = 4527 cycles to do it
do_nothing:
; Try X=4 Y=174 cycles=4525 R2
nop ; 2
ldy #174 ; 2
loop1:
ldx #4 ; 2
loop2:
dex ; 2
bne loop2 ; 2nt/3
dey ; 2
bne loop1 ; 2nt/3
rts ; 6
;==================================
; HLINE
;==================================
; Color in A
; Y has which line
hline:
pha ; 3
ldx gr_offsets,y ; 4+
stx hline_loop+1 ; 4
lda gr_offsets+1,y ; 4+
clc ; 2
adc DRAW_PAGE ; 3
sta hline_loop+2 ; 4
pla ; 4
ldx #39 ; 2
hline_loop:
sta $5d0,X ; 38 ; 5
dex ; 2
bpl hline_loop ; 2nt/3
rts ; 6
;==========================
; Clear gr screen
;==========================
; Color in A
clear_gr:
ldy #46
clear_page_loop:
jsr hline
dey
dey
bpl clear_page_loop
rts
gr_offsets:
.word $400,$480,$500,$580,$600,$680,$700,$780
.word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
.word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0
.include "../asm_routines/gr_unrle.s"
.include "../asm_routines/keypress.s"
.include "gr_copy.s"
pictures:
.word bg_final_low,bg_final_high
.include "background_final.inc"
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