credits: start making it use common infrastructure

This commit is contained in:
Vince Weaver 2018-09-26 16:42:06 -04:00
parent caabb3856e
commit 32a242e9d1
5 changed files with 332 additions and 93 deletions

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@ -33,7 +33,7 @@ RAINBOW.BAS: rainbow.bas
$(TOKENIZE) < rainbow.bas > RAINBOW.BAS
credits.o: credits.s tfv_sprites.inc mockingboard.s \
lz4_decode.s \
lz4_decode.s vapor_lock.s \
KATC.BIN.lz4
ca65 -o credits.o credits.s -l credits.lst

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@ -1,3 +1,7 @@
;
; Cycle-counting text/hgr/lowres demo
; by Vince Weaver
.include "zp.inc"
FRAME = $60
@ -85,61 +89,40 @@ no_init_mb:
;==========================
; setup text screen
lda #0
sta CH
sta CV
lda #<line1
sta OUTL
lda #>line1
sta OUTH
jsr move_and_print
; clear top 6 lines to space
inc CV
jsr move_and_print
; takes (Y/2)*(6+435+7)+5 = ?
lda #$A0 ; space ; 2
ldy #10 ; 6 lines ; 2
jsr clear_page_loop ; 2693???
inc CV
jsr move_and_print
inc CV
jsr move_and_print
inc CV
jsr move_and_print
inc CV
jsr move_and_print
; 1 2
; 0123456789abcdef0123456789abcdef0123456
;line1:.asciiz " * . " $400
;line2:.asciiz " * . . " $480
;line3:.asciiz " * " $500
;line4:.asciiz " * " $580
;line5:.asciiz " . . . " $600
;line6:.asciiz " . " $680
lda #'.'|$80 ; print star ; 2
sta $420 ; 4
sta $487 ; 4
sta $4A4 ; 4
sta $601 ; 4
sta $61c ; 4
sta $621 ; 4
sta $68d ; 4
;============
; 30
; draw the moon
lda #0
sta CV
lda #3
sta CH
jsr htab_vtab ; vtab(1); htab(4)
lda #32 ; inverse space
ldy #0
sta (BASL),Y
inc CV
dec CH
jsr htab_vtab
lda #32
ldy #0
sta (BASL),Y
inc CV
jsr htab_vtab
lda #32
ldy #0
sta (BASL),Y
inc CV
inc CH
jsr htab_vtab
lda #32
ldy #0
sta (BASL),Y
lda #' ' ; print inv space ; 2
sta $403 ; 4
sta $482 ; 4
sta $502 ; 4
sta $583 ; 4
;============
; 18
; test letters
;letter_loop:
; lda #80
@ -149,7 +132,7 @@ no_init_mb:
; Wait
; jsr wait_until_keypressed
jsr wait_until_keypressed
; GR part
bit LORES
@ -171,41 +154,9 @@ no_init_mb:
;=====================================================
; attempt vapor lock
; by reading the "floating bus" we can see most recently
; written value of the display
; we look for $44 (which is the green grass on low-res)
;=====================================================
; See:
; Have an Apple Split by Bob Bishop
; Softalk, October 1982
jsr vapor_lock
; Challenges: each scan line scans 40 bytes.
; The blanking happens at the *beginning*
; So 65 bytes are scanned, starting at adress of the line - 25
; the scan takes 8 cycles, look for 4 repeats of the value
; to avoid false positive found if the horiz blanking is mirroring
; the line (max 3 repeats in that case)
vapor_lock_loop:
LDA #$A0
zxloop:
LDX #$04
wiloop:
CMP $C051
BNE zxloop
DEX
BNE wiloop
LDA #$44
zloop:
LDX #$04
qloop:
CMP $C051
BNE zloop
DEX
BNE qloop
; found first line of low-res green, need to kill time
; until we can enter at top of screen
@ -960,18 +911,17 @@ letters:
.byte 255
line1:.asciiz " * . "
line2:.asciiz " * . . "
line3:.asciiz " * "
line4:.asciiz " * "
line5:.asciiz " . . . "
line6:.asciiz " . "
.include "vapor_lock.s"
.include "delay_a.s"
.include "gr_hline.s"
.include "../asm_routines/text_print.s"
.include "mockingboard.s"
.include "../asm_routines/keypress.s"
.align $100
.include "../asm_routines/gr_offsets.s"
.include "tfv_sprites.inc"
.include "lz4_decode.s"

25
split_screen/delay_a.s Normal file
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@ -0,0 +1,25 @@
; From http://6502org.wikidot.com/software-delay
; 25+A cycles (including JSR), 19 bytes (excluding JSR)
;
; The branches must not cross page boundaries!
;
; Cycles Accumulator Carry flag
; 0 1 2 3 4 5 6 (hex) 0 1 2 3 4 5 6
; jsr delay_a ; 6 6 6 6 6 6 6 00 01 02 03 04 05 06
dly0: sbc #7
delay_a:cmp #7 ; 2 2 2 2 2 2 2 00 01 02 03 04 05 06 0 0 0 0 0 0 0
bcs dly0 ; 2 2 2 2 2 2 2 00 01 02 03 04 05 06 0 0 0 0 0 0 0
lsr ; 2 2 2 2 2 2 2 00 00 01 01 02 02 03 0 1 0 1 0 1 0
bcs dly1 ; 2 3 2 3 2 3 2 00 00 01 01 02 02 03 0 1 0 1 0 1 0
dly1: beq dly2 ; 3 3 2 2 2 2 2 00 00 01 01 02 02 03 0 1 0 1 0 1 0
lsr ; 2 2 2 2 2 00 00 01 01 01 1 1 0 0 1
beq dly3 ; 3 3 2 2 2 00 00 01 01 01 1 1 0 0 1
bcc dly3 ; 3 3 2 01 01 01 0 0 1
dly2: bne dly3 ; 2 2 3 00 00 01 0 1 0
dly3: rts ; 6 6 6 6 6 6 6 00 00 00 00 01 01 01 0 1 1 1 0 0 1
;
; Total cycles: 25 26 27 28 29 30 31

48
split_screen/gr_hline.s Normal file
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@ -0,0 +1,48 @@
;==================================
; HLINE
;==================================
; Color in A
; Y has which line
; takes 435 cycles
hline:
pha ; 3
ldx gr_offsets,y ; 4+
stx hline_loop+1 ; self-modify code ; 4
lda gr_offsets+1,y ; 4+
clc ; 2
adc DRAW_PAGE ; 3
sta hline_loop+2 ; self-modify code ; 4
pla ; 4
ldx #39 ; 2
;===========
; 30
hline_loop:
sta $5d0,X ; 38 ; 5
dex ; 2
bpl hline_loop ; 2nt/3
;===========
; 40*(10)=400
; -1
rts ; 6
;==========================
; Clear gr screen
;==========================
; Color in A, Clears 0 to and including Y
; clear_gr: takes 2+(48/2)*(6+435+7)+5 = 10759
; cpl: takes (Y/2)*(6+435+7)+5 = ?
clear_gr:
ldy #46 ; 2
clear_page_loop:
jsr hline ; 6+435
dey ; 2
dey ; 2
bpl clear_page_loop ; 2/3
rts ; 6
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

216
split_screen/vapor_lock.s Normal file
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@ -0,0 +1,216 @@
; This took a while to track down
; On Apple II/II+ the horiz blanking addr are $1000 higher than on IIe
; So on II+ were outside video area, so unlikely to be our set value
; (unless I foolishly use $ff which some uninitialized mem is set to)
; Lots of this color fiddling is to make sure you don't accidentally
; get runs of colors on IIe due to the horiz blank
; 0-5 aqua 6-12 = grey, 13 - 20 = yellow, 21-23 = aqua rainbow 14
;
;
;16 0 YA
;17 1 YA
;18 2 YA
;19 3 YA
;20 4 YA
;21 5 AA
;22 6 AG
;23 7 AG
;0 8 AG
;1 9 AG
;2 10 AG
;3 11 AG
;4 12 AG
;5 13 AY ****
;6 14 GY RAINBOW
;7 15 GY
;8 16 GY
;9 17 GY
;10 18 GY
;11 19 GY
;12 20 GY
;13 21 YA
;14 22 YA
;15 23 YA
;==============================
; setup graphics for vapor lock
;==============================
vapor_lock:
; Clear Page0
lda #$0
sta DRAW_PAGE
lda #$ee ; full screen white $ff
jsr clear_gr
lda #$dd
ldy #40
jsr clear_page_loop ; make top half grey2 $aa
lda #$aa
ldy #24
jsr clear_page_loop ; make top half grey2 $aa
lda #$ee
ldy #10
jsr clear_page_loop ; make top half grey2 $aa
; set up a rainbow to aid in exact lock
ldy #00
rainbow_loop:
tya
sta $728+20,Y
iny
cpy #20
bne rainbow_loop
;btt:
; jmp btt
;=====================================================
; attempt vapor lock
; by reading the "floating bus" we can see most recently
; written value of the display
;=====================================================
; 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 a full line of $aa
lda #$aa ; 2
zxloop:
ldx #$04 ; 2
wiloop:
cmp $C051 ; read the floating bus ; 4
bne zxloop ; if not, start from scratch ; 2/3
dex ; we were, dec ; 2
bne wiloop ; if not 4 of them, restart ; 3/2
; if we get here we read 4 proper pixels, 11 apart (2+4+2+2+3)
; 0 11 22 33, clock at 34
; 1 12 23 34, clock at 35
; 2 13 24 35, clock at 36
; 3 14 25 36, clock at 37
; 4 15 26 37, clock at 38
; 5 16 27 38, clock at 39
; 6 17 28 39, clock at 40
; X X X X
; X X X X
; X X X X
; X X X X
; X X X X
; X X X X
; X X X X
; 0123456789012345678901234 0123456789012345678901234567890123456789
; 1 2 1 2 3
; hsync pixels
; XXXXXXXXXXXXXXXXXXXXXXXXX 4444444444444444444444444444440123456789
; now look for the color change that
; happens at line 13*8 = 104
lda #$dd ; 2
zloop:
ldx #$04 ; 2
qloop:
cmp $C051 ; read floating bus ; 4
bne zloop ; 2/3
dex ; 2
bne qloop ; 3/2
;============
; 11
; Found it!
; if we get here we read 4 proper pixels, 11 apart (2+4+2+2+3)
; 0 11 22 33, clock at 34
; 1 12 23 34, clock at 35
; 2 13 24 35, clock at 36
; 3 14 25 36, clock at 37
; 4 15 26 37, clock at 38
; 5 16 27 38, clock at 39
; 6 17 28 39, clock at 40
; In theory near end of line 104
; now skip ahead 8 lines and read from the rainbow pattern we set
; up to find our exact location
; delay 65 * 8 = 520
; we back off a few to make sure we're not in the horiz blank
; try to delay 510
lda #230 ; 2
jsr delay_a ; delay 25+230 = 255
lda #226 ; 2
jsr delay_a ; delay 25+226 = 251
; now near end of line 112
lda $C051 ; 4
;kbb:
; jmp kbb
; we are in theory on line $728 = 14*8 = 112
; so 112*65 = 7280 cycles from start
; we are actualy 25+20+A pixels in
; 7325+A
; Our goal is line 114 at 7410 cycles
; 7410 - 7325 = 85
; so kill 85-A cycles
; -6 to do subtraction
; -6 for rts
; -25 for delay_a overhead
eor #$ff ; 2
sec ; 2
adc #48 ; 2
jsr delay_a ; should total 48 cycles
done_vapor_lock:
rts ; 6
; Some random related work
; Docs:
; Lancaster
; Bishop
; Sather
; Vaguely relevant but no help with the Apple II+ issue
;
; Eamon: Screen display and timing synchronization
; on the Apple IIe and Apple IIgs
;
; Adams: Visually presented verbal stimuli by assembly
; language on the Apple II computer.
; Cavanagh and Anstis: Visual psychophysics on the
; Apple II: Getting started