mirror of
https://github.com/deater/dos33fsprogs.git
synced 2025-01-13 22:30:49 +00:00
space_bars: some initial cycle-counting
it would help if I could subtract
This commit is contained in:
Vince Weaver
parent
9a88bc3121
commit
757f9d9c3d
@ -2,6 +2,7 @@ include ../Makefile.inc
|
||||
|
||||
DOS33 = ../dos33fs-utils/dos33
|
||||
PNG_TO_40x48D = ../gr-utils/png_to_40x48d
|
||||
B2D = ../bmp2dhr/b2d
|
||||
|
||||
all: space_bars.dsk
|
||||
|
||||
@ -16,7 +17,8 @@ SPACE_BARS: space_bars.o
|
||||
|
||||
space_bars.o: space_bars.s instructions.s game.s \
|
||||
game_over.s gr_copy.s text_print.s title.s \
|
||||
spacebars_title.inc
|
||||
spacebars_title.inc \
|
||||
vapor_lock.s delay_a.s lz4_decode.s SB_BACKGROUNDC.BIN.lz4
|
||||
ca65 -o space_bars.o space_bars.s -l space_bars.lst
|
||||
|
||||
####
|
||||
@ -24,6 +26,14 @@ space_bars.o: space_bars.s instructions.s game.s \
|
||||
spacebars_title.inc: ./images/spacebars_title_scaled.png
|
||||
$(PNG_TO_40x48D) asm ./images/spacebars_title_scaled.png spacebars_title > spacebars_title.inc
|
||||
|
||||
####
|
||||
|
||||
SB_BACKGROUNDC.BIN.lz4: SB_BACKGROUNDC.BIN
|
||||
lz4 -f -16 SB_BACKGROUNDC.BIN
|
||||
|
||||
SB_BACKGROUNDC.BIN: sb_background.bmp
|
||||
$(B2D) sb_background.bmp HGR -d
|
||||
|
||||
###
|
||||
|
||||
clean:
|
||||
|
||||
25
space_bars/delay_a.s
Normal file
25
space_bars/delay_a.s
Normal file
@ -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
|
||||
@ -1,14 +1,10 @@
|
||||
;================================
|
||||
; Show some instructions
|
||||
; return when a key is pressed
|
||||
; spacebars gameplay
|
||||
;================================
|
||||
|
||||
game:
|
||||
|
||||
;===================
|
||||
; init screen
|
||||
bit LORES
|
||||
bit SET_GR
|
||||
bit FULLGR
|
||||
bit KEYRESET
|
||||
|
||||
;===================
|
||||
@ -17,11 +13,233 @@ game:
|
||||
lda #0
|
||||
sta DRAW_PAGE
|
||||
|
||||
|
||||
;=============================
|
||||
; Load graphic hgr
|
||||
|
||||
lda #<background_hgr
|
||||
sta LZ4_SRC
|
||||
lda #>background_hgr
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda #<(background_hgr_end-8) ; skip checksum at end
|
||||
sta LZ4_END
|
||||
lda #>(background_hgr_end-8) ; skip checksum at end
|
||||
sta LZ4_END+1
|
||||
|
||||
lda #<$2000
|
||||
sta LZ4_DST
|
||||
lda #>$2000
|
||||
sta LZ4_DST+1
|
||||
|
||||
jsr lz4_decode
|
||||
|
||||
|
||||
;=============================
|
||||
; Load graphic page0
|
||||
|
||||
lda #$0c
|
||||
sta BASH
|
||||
lda #$00
|
||||
sta BASL ; load image to $c00
|
||||
|
||||
|
||||
; lda #<fs
|
||||
; sta GBASL
|
||||
; lda #>fs
|
||||
; 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
|
||||
|
||||
;=============================
|
||||
; Load graphic page1
|
||||
|
||||
lda #$0c
|
||||
sta BASH
|
||||
lda #$00
|
||||
sta BASL ; load image to $c00
|
||||
|
||||
; lda #<fs
|
||||
; sta GBASL
|
||||
; lda #>fs
|
||||
; sta GBASH
|
||||
; jsr load_rle_gr
|
||||
|
||||
|
||||
;===================
|
||||
; copy to page3
|
||||
|
||||
lda #0
|
||||
jsr clear_gr
|
||||
sta DRAW_PAGE
|
||||
|
||||
jsr gr_copy_to_current
|
||||
|
||||
; GR part
|
||||
bit PAGE0
|
||||
|
||||
|
||||
jsr wait_until_keypressed ; tail call?
|
||||
;==============================
|
||||
; setup graphics for vapor lock
|
||||
;==============================
|
||||
|
||||
rts
|
||||
jsr vapor_lock ; 6
|
||||
|
||||
; vapor lock returns with us at beginning of hsync in line
|
||||
; 114 (7410 cycles), so with 5070 lines to go
|
||||
|
||||
; so we have 5070 + 4550 = 9620 to kill
|
||||
|
||||
jsr gr_copy_to_current ; 6+ 9292
|
||||
|
||||
; now we have 322 left
|
||||
|
||||
; GR part
|
||||
bit LORES ; 4
|
||||
bit SET_GR ; 4
|
||||
bit FULLGR ; 4
|
||||
|
||||
; 322 - 12 = 310
|
||||
; - 3 for jmp
|
||||
; 307
|
||||
|
||||
; Try X=9 Y=6 cycles=307
|
||||
|
||||
ldy #6 ; 2
|
||||
sbloopA:ldx #9 ; 2
|
||||
sbloopB:dex ; 2
|
||||
bne sbloopB ; 2nt/3
|
||||
dey ; 2
|
||||
bne sbloopA ; 2nt/3
|
||||
|
||||
jmp sb_begin_loop
|
||||
.align $100
|
||||
|
||||
|
||||
;================================================
|
||||
; Spacebars 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
|
||||
|
||||
sb_begin_loop:
|
||||
|
||||
sb_display_loop:
|
||||
|
||||
; 0-7 = text mode
|
||||
; 1 2 3
|
||||
;0123456789012345678901234567890123456789
|
||||
;LEVEL: 6 LIVES: 2 SCORE: 01978 HI: 02018
|
||||
|
||||
; 8-47 = hgr
|
||||
; 48 - 191 = split .. 144 = 36grlins
|
||||
; 6 4 25+16+8+16 NNNNNNNN
|
||||
; 7 6 25+15+10+15 LNNNNNN
|
||||
; 8 8 25+14+12+14 NNNNNNN
|
||||
; 9 10 25+13+14+13 LNNNNN
|
||||
; 10 12 25+12+16+12
|
||||
; 11 14 25+11+18+11
|
||||
; 12 16 25+10+20+10
|
||||
; 13 18 25+09+22+09
|
||||
; 14 20 25+08+24+08
|
||||
; 15 22 25+07+26+07
|
||||
; 16 24 25+06+28+06
|
||||
; 17 26 25+05+30+05
|
||||
; 18 28 25+04+32+04
|
||||
; 19 30 25+03+34+03
|
||||
; 20 32 25+02+36+02
|
||||
; 21 34 25+01+38+01
|
||||
; 22 36 25+00
|
||||
; 23 38 25+12
|
||||
; 24 40 25+12
|
||||
|
||||
|
||||
; 8 lines of text mode
|
||||
|
||||
|
||||
ldy #8 ; 2
|
||||
|
||||
sb_text_loop:
|
||||
bit SET_TEXT ; 4
|
||||
lda #29 ; 2
|
||||
jsr delay_a ; 25+29
|
||||
|
||||
dey ; 2
|
||||
bne sb_text_loop ; 3
|
||||
;================
|
||||
; 65
|
||||
|
||||
|
||||
; -1
|
||||
|
||||
|
||||
sb_hgr_loop:
|
||||
; delay 184*65 = 11960
|
||||
; -2
|
||||
; +1
|
||||
; -8
|
||||
;=========================
|
||||
; 11951
|
||||
|
||||
bit SET_GR ; 4
|
||||
bit HIRES ; 4
|
||||
|
||||
; Try X=22 Y=103 cycles=11949 R2
|
||||
|
||||
nop
|
||||
|
||||
ldy #103 ; 2
|
||||
sbloopC:ldx #22 ; 2
|
||||
sbloopD:dex ; 2
|
||||
bne sbloopD ; 2nt/3
|
||||
dey ; 2
|
||||
bne sbloopC ; 2nt/3
|
||||
|
||||
|
||||
;======================================================
|
||||
; We have 4550 cycles in the vblank, use them wisely
|
||||
;======================================================
|
||||
|
||||
; do_nothing should be 4550
|
||||
; -10 keypress
|
||||
; ===========
|
||||
; 4540
|
||||
|
||||
; Try X=9 Y=89 cycles=4540
|
||||
|
||||
ldy #89 ; 2
|
||||
sbloop1:ldx #9 ; 2
|
||||
sbloop2:dex ; 2
|
||||
bne sbloop2 ; 2nt/3
|
||||
dey ; 2
|
||||
bne sbloop1 ; 2nt/3
|
||||
|
||||
lda KEYPRESS ; 4
|
||||
bpl sb_no_keypress ; 3
|
||||
jmp sb_start_over
|
||||
sb_no_keypress:
|
||||
|
||||
jmp sb_display_loop ; 3
|
||||
|
||||
sb_start_over:
|
||||
bit KEYRESET ; clear keypress ; 4
|
||||
rts ; 6
|
||||
|
||||
|
||||
;.include "deater.inc"
|
||||
background_hgr:
|
||||
.incbin "SB_BACKGROUNDC.BIN.lz4",11
|
||||
background_hgr_end:
|
||||
|
||||
|
||||
213
space_bars/lz4_decode.s
Normal file
213
space_bars/lz4_decode.s
Normal file
@ -0,0 +1,213 @@
|
||||
; LZ4 data decompressor for Apple II
|
||||
|
||||
; Code by Peter Ferrie (qkumba) (peter.ferrie@gmail.com)
|
||||
; "LZ4 unpacker in 143 bytes (6502 version) (2013)"
|
||||
; http://pferrie.host22.com/misc/appleii.htm
|
||||
; This is that code, but with comments and labels added for clarity.
|
||||
; I also found a bug when decoding with runs of multiples of 256
|
||||
; which has since been fixed upstream.
|
||||
|
||||
; For LZ4 reference see
|
||||
; https://github.com/lz4/lz4/wiki/lz4_Frame_format.md
|
||||
|
||||
; LZ4 summary:
|
||||
;
|
||||
; HEADER:
|
||||
; Should: check for magic number 04 22 4d 18
|
||||
; FLG: 64 in our case (01=version, block.index=1, block.checksum=0
|
||||
; size=0, checksum=1, reserved
|
||||
; MAX Blocksize: 40 (64kB)
|
||||
; HEADER CHECKSUM: a7
|
||||
; BLOCK HEADER: 4 bytes (le) length If highest bit set, uncompressed!
|
||||
; data (see below), followed by checksum?
|
||||
; BLOCKS:
|
||||
; Token byte. High 4-bits literal length, low 4-bits copy length
|
||||
; + If literal length==15, then following byte gets added to length
|
||||
; If that byte was 255, then keep adding bytes until not 255
|
||||
; + The literal bytes follow. There may be zero of them
|
||||
; + Next is block copy info. little-endian 2-byte offset to
|
||||
; be subtracted from current read position indicating source
|
||||
; + The low 4-bits of the token are the copy length, which needs
|
||||
; 4 added to it. As with the literal length, if it is 15 then
|
||||
; you read a byte and add (and if that byte is 255, keep adding)
|
||||
|
||||
; At end you have 4 byte end-of-block marker (all zeros?) then
|
||||
; 4 bytes of checksum (if marked in flags)
|
||||
; our code does that, so be sure to set end -8
|
||||
|
||||
|
||||
;LZ4_SRC EQU $00
|
||||
;LZ4_DST EQU $02
|
||||
;LZ4_END EQU $04
|
||||
;COUNT EQU $06
|
||||
;DELTA EQU $08
|
||||
|
||||
;UNPACK_BUFFER EQU $5E00 ; offset of first unpacked byte
|
||||
|
||||
|
||||
;======================
|
||||
; LZ4 decode
|
||||
;======================
|
||||
; input buffer in LZ4_SRC
|
||||
; output buffer hardcoded still
|
||||
; size in ENDH:ENDL
|
||||
|
||||
lz4_decode:
|
||||
; lda LZ4_SRC ; packed data offset
|
||||
; clc
|
||||
; adc LZ4_END
|
||||
; sta LZ4_END
|
||||
; lda LZ4_SRC+1
|
||||
; adc LZ4_END+1
|
||||
; sta LZ4_END+1
|
||||
|
||||
; lda #>UNPACK_BUFFER ; original unpacked data offset
|
||||
; sta LZ4_DST+1
|
||||
; lda #<UNPACK_BUFFER
|
||||
; sta LZ4_DST
|
||||
|
||||
unpmain:
|
||||
ldy #0 ; used to index, always zero
|
||||
|
||||
parsetoken:
|
||||
jsr getsrc ; get next token
|
||||
pha ; save for later (need bottom 4 bits)
|
||||
|
||||
lsr ; number of literals in top 4 bits
|
||||
lsr ; so shift into place
|
||||
lsr
|
||||
lsr
|
||||
beq copymatches ; if zero, then no literals
|
||||
; jump ahead and copy
|
||||
|
||||
jsr buildcount ; add up all the literal sizes
|
||||
; result is in ram[count+1]-1:A
|
||||
tax ; now in ram[count+1]-1:X
|
||||
jsr docopy ; copy the literals
|
||||
|
||||
lda LZ4_SRC ; 16-bit compare
|
||||
cmp LZ4_END ; to see if we have reached the end
|
||||
lda LZ4_SRC+1
|
||||
sbc LZ4_END+1
|
||||
bcs done
|
||||
|
||||
copymatches:
|
||||
jsr getsrc ; get 16-bit delta value
|
||||
sta DELTA
|
||||
jsr getsrc
|
||||
sta DELTA+1
|
||||
|
||||
pla ; restore token
|
||||
and #$0f ; get bottom 4 bits
|
||||
; match count. 0 means 4
|
||||
; 15 means 19+, must be calculated
|
||||
|
||||
jsr buildcount ; add up count bits, in ram[count+1]-:A
|
||||
|
||||
clc
|
||||
adc #4 ; adjust count by 4 (minmatch)
|
||||
|
||||
tax ; now in ramp[count+1]-1:X
|
||||
|
||||
beq copy_no_adjust ; BUGFIX, don't increment if
|
||||
; exactly a multiple of 0x100
|
||||
bcc copy_no_adjust
|
||||
|
||||
inc COUNT+1 ; increment if we overflowed
|
||||
copy_no_adjust:
|
||||
|
||||
lda LZ4_SRC+1 ; save src on stack
|
||||
pha
|
||||
lda LZ4_SRC
|
||||
pha
|
||||
|
||||
sec ; subtract delta
|
||||
lda LZ4_DST ; from destination, make new src
|
||||
sbc DELTA
|
||||
sta LZ4_SRC
|
||||
lda LZ4_DST+1
|
||||
sbc DELTA+1
|
||||
sta LZ4_SRC+1
|
||||
|
||||
jsr docopy ; do the copy
|
||||
|
||||
pla ; restore the src
|
||||
sta LZ4_SRC
|
||||
pla
|
||||
sta LZ4_SRC+1
|
||||
|
||||
jmp parsetoken ; back to parsing tokens
|
||||
|
||||
done:
|
||||
pla
|
||||
rts
|
||||
|
||||
;=========
|
||||
; getsrc
|
||||
;=========
|
||||
; gets byte from src into A, increments pointer
|
||||
getsrc:
|
||||
lda (LZ4_SRC), Y ; get a byte from src
|
||||
inc LZ4_SRC ; increment pointer
|
||||
bne done_getsrc ; update 16-bit pointer
|
||||
inc LZ4_SRC+1 ; on 8-bit overflow
|
||||
done_getsrc:
|
||||
rts
|
||||
|
||||
;============
|
||||
; buildcount
|
||||
;============
|
||||
buildcount:
|
||||
ldx #1 ; high count starts at 1
|
||||
stx COUNT+1 ; (loops at zero?)
|
||||
cmp #$0f ; if LITERAL_COUNT < 15, we are done
|
||||
bne done_buildcount
|
||||
buildcount_loop:
|
||||
sta COUNT ; save LITERAL_COUNT (15)
|
||||
jsr getsrc ; get the next byte
|
||||
tax ; put in X
|
||||
clc
|
||||
adc COUNT ; add new byte to old value
|
||||
bcc bc_8bit_oflow ; if overflow, increment high byte
|
||||
inc COUNT+1
|
||||
bc_8bit_oflow:
|
||||
inx ; check if read value was 255
|
||||
beq buildcount_loop ; if it was, keep looping and adding
|
||||
done_buildcount:
|
||||
rts
|
||||
|
||||
;============
|
||||
; getput
|
||||
;============
|
||||
; gets a byte, then puts the byte
|
||||
getput:
|
||||
jsr getsrc
|
||||
; fallthrough to putdst
|
||||
|
||||
;=============
|
||||
; putdst
|
||||
;=============
|
||||
; store A into destination
|
||||
putdst:
|
||||
sta (LZ4_DST), Y ; store A into destination
|
||||
inc LZ4_DST ; increment 16-bit pointer
|
||||
bne putdst_end ; if overflow, increment top byte
|
||||
inc LZ4_DST+1
|
||||
putdst_end:
|
||||
rts
|
||||
|
||||
;=============================
|
||||
; docopy
|
||||
;=============================
|
||||
; copies ram[count+1]-1:X bytes
|
||||
; from src to dst
|
||||
docopy:
|
||||
|
||||
docopy_loop:
|
||||
jsr getput ; get/put byte
|
||||
dex ; decrement count
|
||||
bne docopy_loop ; if not zero, loop
|
||||
dec COUNT+1 ; if zero, decrement high byte
|
||||
bne docopy_loop ; if not zero, loop
|
||||
|
||||
rts
|
||||
@ -8,6 +8,16 @@
|
||||
|
||||
; Zero Page
|
||||
FRAMEBUFFER = $00 ; $00 - $0F
|
||||
|
||||
;; LZ4 addresses
|
||||
|
||||
LZ4_SRC = $00
|
||||
LZ4_DST = $02
|
||||
LZ4_END = $04
|
||||
COUNT = $06
|
||||
DELTA = $08
|
||||
|
||||
|
||||
YPOS = $10
|
||||
YPOS_SIN = $11
|
||||
CH = $24
|
||||
@ -29,14 +39,18 @@ OUTH = $FF
|
||||
KEYPRESS= $C000
|
||||
KEYRESET= $C010
|
||||
SET_GR = $C050 ; Enable graphics
|
||||
SET_TEXT= $C051 ; Enable text
|
||||
FULLGR = $C052 ; Full screen, no text
|
||||
PAGE0 = $C054 ; Page0
|
||||
PAGE1 = $C055 ; Page1
|
||||
LORES = $C056 ; Enable LORES graphics
|
||||
HIRES = $C057 ; Enable HIRES graphics
|
||||
PADDLE_BUTTON0 = $C061
|
||||
PADDL0 = $C064
|
||||
PTRIG = $C070
|
||||
|
||||
|
||||
|
||||
; ROM routines
|
||||
|
||||
TEXT = $FB36 ;; Set text mode
|
||||
@ -129,6 +143,9 @@ gr_offsets:
|
||||
.include "game.s"
|
||||
.include "text_print.s"
|
||||
.include "game_over.s"
|
||||
.include "vapor_lock.s"
|
||||
.include "delay_a.s"
|
||||
.include "lz4_decode.s"
|
||||
|
||||
.include "spacebars_title.inc"
|
||||
|
||||
|
||||
@ -65,55 +65,7 @@ title_screen:
|
||||
;==============================
|
||||
; 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
|
||||
jsr vapor_lock
|
||||
|
||||
; 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
|
||||
|
||||
216
space_bars/vapor_lock.s
Normal file
216
space_bars/vapor_lock.s
Normal file
@ -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
|
||||
Loading…
x
Reference in New Issue
Block a user