mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-12-25 20:30:31 +00:00
dya: more work on playing two tracks at once
This commit is contained in:
Vince Weaver
parent
6146f3a229
commit
f5c91a3097
@ -22,9 +22,8 @@ CHIPTUNE_PLAYER: chiptune_player.o
|
||||
ld65 -o CHIPTUNE_PLAYER chiptune_player.o -C ../linker_scripts/apple2_800.inc
|
||||
|
||||
chiptune_player.o: chiptune_player.s \
|
||||
../asm_routines/mockingboard.s \
|
||||
../asm_routines/dos33_routines.s \
|
||||
../asm_routines/lz4_decode.s \
|
||||
mockingboard_a.s \
|
||||
lz4_decode.s \
|
||||
../asm_routines/keypress_minimal.s \
|
||||
rasterbars.s volume_bars.s interrupt_handler.s qkumba_rts.s \
|
||||
chip_title_uncompressed.inc zp.inc
|
||||
|
||||
@ -2,10 +2,10 @@
|
||||
|
||||
.include "zp.inc"
|
||||
; program is ~4k, so from 0xc00 to 0x1C00
|
||||
LZ4_BUFFER EQU $1C00 ; $1C00 - $5C00, 16k for now
|
||||
DISK_BUFFER EQU $5D00 ; for disk loading
|
||||
UNPACK_BUFFER EQU $6000 ; $6000 - $9800, 14k, $3800
|
||||
|
||||
LZ4_BUFFER EQU $1C00 ; $1C00 - $4400, 10k = $2800
|
||||
DISK_BUFFER EQU $4400 ; for disk loading
|
||||
UNPACK_BUFFER1 EQU $5000 ; $5000 - $8800, 14k, $3800
|
||||
UNPACK_BUFFER2 EQU $8800 ; $8800 - $C000, 14k, $3800
|
||||
; by using qkumba's RTS code
|
||||
; no need for DOS, so we actually
|
||||
; are free the whole way to $C000
|
||||
@ -13,7 +13,7 @@ UNPACK_BUFFER EQU $6000 ; $6000 - $9800, 14k, $3800
|
||||
; $6000 - $C000 = 24k
|
||||
|
||||
|
||||
NUM_FILES EQU 15
|
||||
NUM_FILES EQU 2
|
||||
|
||||
|
||||
jmp chiptune_setup
|
||||
@ -126,32 +126,6 @@ mockingboard_found:
|
||||
; 4fe7 / 1e6 = .020s, 50Hz
|
||||
|
||||
|
||||
;============================
|
||||
; Draw title screen
|
||||
;============================
|
||||
|
||||
; jsr set_gr_page0 ; set page 0
|
||||
|
||||
; lda #$4 ; draw page 1
|
||||
; sta DRAW_PAGE
|
||||
|
||||
; jsr clear_screens ; clear both screens
|
||||
|
||||
; lda #<chip_title ; point to title data
|
||||
; sta GBASL
|
||||
; lda #>chip_title
|
||||
; sta GBASH
|
||||
|
||||
; bit PAGE1
|
||||
|
||||
; Load image ; load the image
|
||||
; lda #<$800
|
||||
; sta BASL
|
||||
; lda #>$800
|
||||
; sta BASH
|
||||
|
||||
; jsr load_rle_gr
|
||||
|
||||
;==================
|
||||
; load first song
|
||||
;==================
|
||||
@ -213,14 +187,6 @@ check_decompress:
|
||||
lda #0
|
||||
sta DECOMPRESS_TIME
|
||||
|
||||
;============================
|
||||
; visualization
|
||||
;============================
|
||||
; jsr clear_top
|
||||
; jsr draw_rasters
|
||||
; jsr volume_bars
|
||||
; jsr page_flip
|
||||
|
||||
check_done:
|
||||
lda #$ff
|
||||
bit DONE_PLAYING
|
||||
@ -397,10 +363,6 @@ done_name_loop:
|
||||
sta $777
|
||||
sta $B77
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
; Point LZ4 src at proper place
|
||||
|
||||
ldy #0
|
||||
@ -417,9 +379,9 @@ done_name_loop:
|
||||
adc #0
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda #<UNPACK_BUFFER ; set input pointer
|
||||
lda #<UNPACK_BUFFER1 ; set input pointer
|
||||
sta INL
|
||||
lda #>UNPACK_BUFFER
|
||||
lda #>UNPACK_BUFFER1
|
||||
sta INH
|
||||
|
||||
; Decompress first chunks
|
||||
@ -433,6 +395,14 @@ done_name_loop:
|
||||
sta DECODER_STATE
|
||||
sta COPY_TIME
|
||||
|
||||
lda LZ4_SRC
|
||||
sta LZ4_SRC1
|
||||
sta LZ4_SRC2
|
||||
|
||||
lda LZ4_SRC+1
|
||||
sta LZ4_SRC1+1
|
||||
sta LZ4_SRC2+1
|
||||
|
||||
jsr setup_next_subsong
|
||||
|
||||
rts
|
||||
@ -442,8 +412,16 @@ done_name_loop:
|
||||
;=================
|
||||
setup_next_subsong:
|
||||
|
||||
;==============
|
||||
; Left side
|
||||
|
||||
ldy #0
|
||||
|
||||
lda LZ4_SRC1
|
||||
sta LZ4_SRC
|
||||
lda LZ4_SRC1+1
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda (LZ4_SRC),Y ; get next size value
|
||||
sta LZ4_END
|
||||
iny
|
||||
@ -458,8 +436,57 @@ setup_next_subsong:
|
||||
adc #0
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda #>UNPACK_BUFFER1 ; original unpacked data offset
|
||||
sta LZ4_DST+1
|
||||
lda #<UNPACK_BUFFER1
|
||||
sta LZ4_DST
|
||||
|
||||
|
||||
jsr lz4_decode ; decode
|
||||
|
||||
lda LZ4_SRC
|
||||
sta LZ4_SRC1
|
||||
lda LZ4_SRC+1
|
||||
sta LZ4_SRC1+1
|
||||
|
||||
;==================
|
||||
; right side
|
||||
|
||||
ldy #0
|
||||
|
||||
lda LZ4_SRC2
|
||||
sta LZ4_SRC
|
||||
lda LZ4_SRC2+1
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda (LZ4_SRC),Y ; get next size value
|
||||
sta LZ4_END
|
||||
iny
|
||||
lda (LZ4_SRC),Y
|
||||
sta LZ4_END+1
|
||||
|
||||
lda #2 ; increment pointer
|
||||
clc
|
||||
adc LZ4_SRC
|
||||
sta LZ4_SRC
|
||||
lda LZ4_SRC+1
|
||||
adc #0
|
||||
sta LZ4_SRC+1
|
||||
|
||||
lda #>UNPACK_BUFFER1 ; original unpacked data offset
|
||||
sta LZ4_DST+1
|
||||
lda #<UNPACK_BUFFER1
|
||||
sta LZ4_DST
|
||||
|
||||
|
||||
jsr lz4_decode ; decode
|
||||
|
||||
lda LZ4_SRC
|
||||
sta LZ4_SRC2
|
||||
lda LZ4_SRC+1
|
||||
sta LZ4_SRC2+1
|
||||
|
||||
|
||||
; tail-call?
|
||||
|
||||
rts
|
||||
@ -513,13 +540,13 @@ bloop22:
|
||||
; DST: chunk_buffer+$2A00+(COPY_OFFSET*256)
|
||||
page_copy:
|
||||
clc ; 2
|
||||
lda #>(UNPACK_BUFFER+512) ; 3
|
||||
lda #>(UNPACK_BUFFER1+512) ; 3
|
||||
adc COPY_OFFSET ; 3
|
||||
adc COPY_OFFSET ; 3
|
||||
adc COPY_OFFSET ; 3
|
||||
sta page_copy_loop+2 ; self modify ; 5
|
||||
|
||||
lda #>(UNPACK_BUFFER+$2A00) ; 2
|
||||
lda #>(UNPACK_BUFFER1+$2A00) ; 2
|
||||
adc COPY_OFFSET ; 3
|
||||
sta page_copy_loop+5 ; self modify ; 5
|
||||
|
||||
@ -613,14 +640,14 @@ krw_file:
|
||||
;=========
|
||||
.include "../asm_routines/gr_offsets.s"
|
||||
.include "text_print.s"
|
||||
.include "../asm_routines/mockingboard_a.s"
|
||||
.include "mockingboard_a.s"
|
||||
.include "../asm_routines/gr_fast_clear.s"
|
||||
.include "../asm_routines/pageflip.s"
|
||||
;.include "../asm_routines/gr_unrle.s"
|
||||
.include "../asm_routines/gr_setpage.s"
|
||||
.include "qkumba_rts.s"
|
||||
.include "../asm_routines/gr_hlin.s"
|
||||
.include "../asm_routines/lz4_decode.s"
|
||||
.include "lz4_decode.s"
|
||||
.include "../asm_routines/keypress_minimal.s"
|
||||
.include "rasterbars.s"
|
||||
.include "volume_bars.s"
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
5 PRINT
|
||||
5 GR
|
||||
10 PRINT "LOADING VMW CHIPTUNE PLAYER"
|
||||
20 PRINT "DYA SPECIAL EDITION V1.0"
|
||||
50 PRINT
|
||||
50 PRINT: X=PEEK(49237)
|
||||
100 PRINT CHR$ (4)"BRUN CHIPTUNE_PLAYER"
|
||||
|
||||
@ -225,12 +225,12 @@ back_to_first_reg_b:
|
||||
|
||||
back_to_first_reg_a:
|
||||
clc ; 2
|
||||
adc #>UNPACK_BUFFER ; in proper chunk 1 or 2 ; 2
|
||||
adc #>UNPACK_BUFFER1 ; in proper chunk 1 or 2 ; 2
|
||||
|
||||
jmp update_r0_pointer ; 3
|
||||
|
||||
back_to_first_reg_c:
|
||||
lda #>(UNPACK_BUFFER+$2A00) ; in linear C area ; 2
|
||||
lda #>(UNPACK_BUFFER1+$2A00) ; in linear C area ; 2
|
||||
|
||||
update_r0_pointer:
|
||||
sta INH ; update r0 pointer ; 3
|
||||
|
||||
207
dya/lz4_decode.s
Normal file
207
dya/lz4_decode.s
Normal file
@ -0,0 +1,207 @@
|
||||
; 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) If highest bit set, uncompressed!
|
||||
; 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)
|
||||
|
||||
;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
|
||||
206
dya/mockingboard_a.s
Normal file
206
dya/mockingboard_a.s
Normal file
@ -0,0 +1,206 @@
|
||||
; Mockingboad programming:
|
||||
; + Has two 6522 I/O chips connected to two AY-3-8910 chips
|
||||
; + Optionally has some speech chips controlled via the outport on the AY
|
||||
; + Often in slot 4
|
||||
; TODO: how to auto-detect?
|
||||
; References used:
|
||||
; http://macgui.com/usenet/?group=2&id=8366
|
||||
; 6522 Data Sheet
|
||||
; AY-3-8910 Data Sheet
|
||||
|
||||
;========================
|
||||
; Mockingboard card
|
||||
; Essentially two 6522s hooked to the Apple II bus
|
||||
; Connected to AY-3-8910 chips
|
||||
; PA0-PA7 on 6522 connected to DA0-DA7 on AY
|
||||
; PB0 on 6522 connected to BC1
|
||||
; PB1 on 6522 connected to BDIR
|
||||
; PB2 on 6522 connected to RESET
|
||||
|
||||
|
||||
; left speaker
|
||||
MOCK_6522_ORB1 EQU $C400 ; 6522 #1 port b data
|
||||
MOCK_6522_ORA1 EQU $C401 ; 6522 #1 port a data
|
||||
MOCK_6522_DDRB1 EQU $C402 ; 6522 #1 data direction port B
|
||||
MOCK_6522_DDRA1 EQU $C403 ; 6522 #1 data direction port A
|
||||
|
||||
; right speaker
|
||||
MOCK_6522_ORB2 EQU $C480 ; 6522 #2 port b data
|
||||
MOCK_6522_ORA2 EQU $C481 ; 6522 #2 port a data
|
||||
MOCK_6522_DDRB2 EQU $C482 ; 6522 #2 data direction port B
|
||||
MOCK_6522_DDRA2 EQU $C483 ; 6522 #2 data direction port A
|
||||
|
||||
; AY-3-8910 commands on port B
|
||||
; RESET BDIR BC1
|
||||
MOCK_AY_RESET EQU $0 ; 0 0 0
|
||||
MOCK_AY_INACTIVE EQU $4 ; 1 0 0
|
||||
MOCK_AY_READ EQU $5 ; 1 0 1
|
||||
MOCK_AY_WRITE EQU $6 ; 1 1 0
|
||||
MOCK_AY_LATCH_ADDR EQU $7 ; 1 1 1
|
||||
|
||||
|
||||
;========================
|
||||
; Mockingboard Init
|
||||
;========================
|
||||
; Initialize the 6522s
|
||||
; set the data direction for all pins of PortA/PortB to be output
|
||||
|
||||
mockingboard_init:
|
||||
lda #$ff ; all output (1)
|
||||
sta MOCK_6522_DDRB1
|
||||
sta MOCK_6522_DDRA1
|
||||
sta MOCK_6522_DDRB2
|
||||
sta MOCK_6522_DDRA2
|
||||
rts
|
||||
|
||||
;======================
|
||||
; Reset Left AY-3-8910
|
||||
;======================
|
||||
reset_ay_both:
|
||||
lda #MOCK_AY_RESET
|
||||
sta MOCK_6522_ORB1
|
||||
lda #MOCK_AY_INACTIVE
|
||||
sta MOCK_6522_ORB1
|
||||
|
||||
;======================
|
||||
; Reset Right AY-3-8910
|
||||
;======================
|
||||
;reset_ay_right:
|
||||
lda #MOCK_AY_RESET
|
||||
sta MOCK_6522_ORB2
|
||||
lda #MOCK_AY_INACTIVE
|
||||
sta MOCK_6522_ORB2
|
||||
rts
|
||||
|
||||
|
||||
; Write sequence
|
||||
; Inactive -> Latch Address -> Inactive -> Write Data -> Inactive
|
||||
|
||||
;=========================================
|
||||
; Write Right/Left to save value AY-3-8910
|
||||
;=========================================
|
||||
; register in X
|
||||
; value in MB_VALUE
|
||||
|
||||
write_ay_both:
|
||||
; address
|
||||
stx MOCK_6522_ORA1 ; put address on PA1 ; 3
|
||||
stx MOCK_6522_ORA2 ; put address on PA2 ; 3
|
||||
lda #MOCK_AY_LATCH_ADDR ; latch_address on PB1 ; 2
|
||||
sta MOCK_6522_ORB1 ; latch_address on PB1 ; 3
|
||||
sta MOCK_6522_ORB2 ; latch_address on PB2 ; 3
|
||||
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
||||
sta MOCK_6522_ORB1 ; 3
|
||||
sta MOCK_6522_ORB2 ; 3
|
||||
|
||||
; value
|
||||
lda MB_VALUE ; 3
|
||||
sta MOCK_6522_ORA1 ; put value on PA1 ; 3
|
||||
sta MOCK_6522_ORA2 ; put value on PA2 ; 3
|
||||
lda #MOCK_AY_WRITE ; ; 2
|
||||
sta MOCK_6522_ORB1 ; write on PB1 ; 3
|
||||
sta MOCK_6522_ORB2 ; write on PB2 ; 3
|
||||
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
||||
sta MOCK_6522_ORB1 ; 3
|
||||
sta MOCK_6522_ORB2 ; 3
|
||||
|
||||
rts ; 6
|
||||
;===========
|
||||
; 53
|
||||
;=======================================
|
||||
; clear ay -- clear all 14 AY registers
|
||||
; should silence the card
|
||||
;=======================================
|
||||
clear_ay_both:
|
||||
ldx #14
|
||||
lda #0
|
||||
sta MB_VALUE
|
||||
clear_ay_left_loop:
|
||||
jsr write_ay_both
|
||||
dex
|
||||
bpl clear_ay_left_loop
|
||||
rts
|
||||
|
||||
;=======================================
|
||||
; Detect a Mockingboard card
|
||||
;=======================================
|
||||
; Based on code from the French Touch "Pure Noise" Demo
|
||||
; Attempts to time an instruction sequence with a 6522
|
||||
;
|
||||
; If found, puts in bMB
|
||||
; MB_ADDRL:MB_ADDRH has address of Mockingboard
|
||||
; returns X=0 if not found, X=1 if found
|
||||
|
||||
mockingboard_detect:
|
||||
lda #0
|
||||
sta MB_ADDRL
|
||||
|
||||
mb_detect_loop: ; self-modifying
|
||||
lda #$07 ; we start in slot 7 ($C7) and go down to 0 ($C0)
|
||||
ora #$C0 ; make it start with C
|
||||
sta MB_ADDRH
|
||||
ldy #04 ; $CX04
|
||||
ldx #02 ; 2 tries?
|
||||
mb_check_cycle_loop:
|
||||
lda (MB_ADDRL),Y ; timer 6522 (Low Order Counter)
|
||||
; count down
|
||||
sta TEMP ; 3 cycles
|
||||
lda (MB_ADDRL),Y ; + 5 cycles = 8 cycles
|
||||
; between the two accesses to the timer
|
||||
sec
|
||||
sbc TEMP ; subtract to see if we had 8 cycles
|
||||
cmp #$f8 ; -8
|
||||
bne mb_not_in_this_slot
|
||||
dex ; decrement, try one more time
|
||||
bne mb_check_cycle_loop ; loop detection
|
||||
inx ; Mockingboard found (X=1)
|
||||
done_mb_detect:
|
||||
;stx bMB ; store result to bMB
|
||||
rts ; return
|
||||
|
||||
mb_not_in_this_slot:
|
||||
dec mb_detect_loop+1 ; decrement the "slot" (self_modify)
|
||||
bne mb_detect_loop ; loop down to one
|
||||
ldx #00
|
||||
beq done_mb_detect
|
||||
|
||||
|
||||
;=======================================
|
||||
; Detect a Mockingboard card in Slot4
|
||||
;=======================================
|
||||
; Based on code from the French Touch "Pure Noise" Demo
|
||||
; Attempts to time an instruction sequence with a 6522
|
||||
;
|
||||
; MB_ADDRL:MB_ADDRH has address of Mockingboard
|
||||
; returns X=0 if not found, X=1 if found
|
||||
|
||||
mockingboard_detect_slot4:
|
||||
lda #0
|
||||
sta MB_ADDRL
|
||||
|
||||
mb4_detect_loop: ; self-modifying
|
||||
lda #$04 ; we're only looking in Slot 4
|
||||
ora #$C0 ; make it start with C
|
||||
sta MB_ADDRH
|
||||
ldy #04 ; $CX04
|
||||
ldx #02 ; 2 tries?
|
||||
mb4_check_cycle_loop:
|
||||
lda (MB_ADDRL),Y ; timer 6522 (Low Order Counter)
|
||||
; count down
|
||||
sta TEMP ; 3 cycles
|
||||
lda (MB_ADDRL),Y ; + 5 cycles = 8 cycles
|
||||
; between the two accesses to the timer
|
||||
sec
|
||||
sbc TEMP ; subtract to see if we had 8 cycles
|
||||
cmp #$f8 ; -8
|
||||
bne mb4_not_in_this_slot
|
||||
dex ; decrement, try one more time
|
||||
bne mb4_check_cycle_loop ; loop detection
|
||||
inx ; Mockingboard found (X=1)
|
||||
done_mb4_detect:
|
||||
rts ; return
|
||||
|
||||
mb4_not_in_this_slot:
|
||||
ldx #00
|
||||
beq done_mb4_detect
|
||||
|
||||
@ -1,2 +1,3 @@
|
||||
.asciiz "DOTD1.KRW"
|
||||
.asciiz "DOTD2.KRW"
|
||||
|
||||
|
||||
@ -5,6 +5,8 @@ LZ4_DST EQU $02
|
||||
LZ4_END EQU $04
|
||||
COUNT EQU $06
|
||||
DELTA EQU $08
|
||||
LZ4_SRC1 EQU $0A
|
||||
LZ4_SRC2 EQU $0C
|
||||
|
||||
;; Zero page monitor routines addresses
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user