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dos33fsprogs
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tiny_tracker: get it working

This commit is contained in:
Vince Weaver 2022-01-15 15:07:13 -05:00
parent 307a8ec58b
commit 53f9fc0bc2
5 changed files with 100 additions and 112 deletions
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2
demos/l/d4/Makefile
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@ -57,7 +57,7 @@ D2: d2.o
d2.o: d2.s \
zp.inc hardware.inc \
mA2E_2.s mA2E_3.s \
interrupt_handler.s mockingboard_init.s \
interrupt_handler.s mockingboard_init.s play_frame.s \
tracker_init.s mockingboard_constants.s ay3_write_regs.s
ca65 -o d2.o d2.s -l d2.lst

2
demos/l/d4/d2.s
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@ -8,7 +8,7 @@
; aiming for under 256
; 309 bytes -- first try
; 310 bytes -- initial
; if can straddle interrupt vector, save 10 bytes

110
demos/l/d4/interrupt_handler.s
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@ -40,116 +40,8 @@ ay3_irq_handler:
bit MOCK_6522_T1CL
; drop note down after first
; lda #$C
; sta AY_REGS+8
; sta AY_REGS+9
; sta AY_REGS+10
lda #$0E
sta AY_REGS+8 ; $08 volume A
lda #$0C
sta AY_REGS+9 ; $09 volume B
sta AY_REGS+10 ; $0A volume C
;============================
; see if still counting down
lda SONG_COUNTDOWN
bpl done_update_song
set_notes_loop:
;==================
; load next byte
ldy SONG_OFFSET
lda tracker_song,Y
;==================
; see if hit end
cmp #$FF
bne all_ok
;====================================
; if at end, loop back to beginning
lda #0 ; reset song offset
sta SONG_OFFSET
beq set_notes_loop ; bra
all_ok:
; see if note
; tay
; and #$C0
; cmp #$C0
; beq handle_timing
note_only:
; tya
; NNNNNECC -- c=channel, n=note
tay ; save note in Y
and #3
asl
tax ; put channel offset in X
lda #$2 ; always 4 lines long
sta SONG_COUNTDOWN
tya
lsr
lsr
lsr ; get note in A
tay ; lookup in table
lda frequencies_low,Y
sta AY_REGS,X ; set proper register value
lda frequencies_high,Y
sta AY_REGS+1,X
lda #$F
sta AY_REGS+8
;============================
; point to next
; assume less than 256 bytes
inc SONG_OFFSET
lda SONG_COUNTDOWN
beq set_notes_loop ; bra
.include "ay3_write_regs.s"
; jsr ay3_write_regs
handle_timing:
; was timing
; tya
; and #$3f
; sta SONG_COUNTDOWN
; inc SONG_OFFSET
done_update_song:
dec SONG_COUNTDOWN
.include "play_frame.s"
;=================================

96
demos/l/d4/play_frame.s Normal file
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@ -0,0 +1,96 @@
play_frame:
; drop note down after first
; lda #$C
; sta AY_REGS+8
; sta AY_REGS+9
; sta AY_REGS+10
lda #$0E
sta AY_REGS+8 ; $08 volume A
lda #$0C
sta AY_REGS+9 ; $09 volume B
sta AY_REGS+10 ; $0A volume C
;============================
; see if still counting down
lda SONG_COUNTDOWN
bpl done_update_song
set_notes_loop:
;==================
; load next byte
ldy SONG_OFFSET
lda tracker_song,Y
;==================
; see if hit end
cmp #$FF
bne all_ok
;====================================
; if at end, loop back to beginning
lda #0 ; reset song offset
sta SONG_OFFSET
beq set_notes_loop ; bra
all_ok:
note_only:
; NNNNNECC -- c=channel, e=end, n=note
tay ; save note in Y
and #3
asl
tax ; put channel offset in X
tya
and #$4
sta SONG_COUNTDOWN ; always 4 long?
tya
lsr
lsr
lsr ; get note in A
tay ; lookup in table
lda frequencies_low,Y
sta AY_REGS,X ; set proper register value
lda frequencies_high,Y
sta AY_REGS+1,X
lda #$F
sta AY_REGS+8
;============================
; point to next
; assume less than 256 bytes
inc SONG_OFFSET
lda SONG_COUNTDOWN
beq set_notes_loop ; bra
.include "ay3_write_regs.s"
done_update_song:
dec SONG_COUNTDOWN

2
demos/l/d4/text_to_tiny.c
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@ -214,7 +214,7 @@ static int write_note(int *a_last,int *b_last,int *c_last,int *total_len) {
if (*a_last>=0) {
temp_value=(*a_last<<3)|0;
if ((*b_last<0) || (*c_last<0)) {
if ((*b_last<0) && (*c_last<0)) {
temp_value|=4;
}
printf("\t.byte $%02X ; A=%d L=%d\n",