mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-09 07:09:55 +00:00
460 lines
9.7 KiB
ArmAsm
460 lines
9.7 KiB
ArmAsm
;================================
|
|
;================================
|
|
; mockingboard interrupt handler
|
|
;================================
|
|
;================================
|
|
; On Apple II/6502 the interrupt handler jumps to address in 0xfffe
|
|
; This is in the ROM, which saves the registers
|
|
; on older IIe it saved A to $45 (which could mess with DISK II)
|
|
; newer IIe doesn't do that.
|
|
; It then calculates if it is a BRK or not (which trashes A)
|
|
; Then it sets up the stack like an interrupt and calls 0x3fe
|
|
|
|
TIME_OFFSET EQU 13
|
|
|
|
interrupt_handler:
|
|
; pha ; save A ; 3
|
|
; A is saved in $45 by firmware
|
|
txa
|
|
pha ; save X
|
|
tya
|
|
pha ; save Y
|
|
|
|
|
|
|
|
; inc $0404 ; debug (flashes char onscreen)
|
|
|
|
bit $C404 ; clear 6522 interrupt by reading T1C-L ; 4
|
|
|
|
|
|
lda DONE_PLAYING ; 3
|
|
beq mb_play_music ; if song done, don't play music ; 3/2nt
|
|
jmp check_keyboard ; 3
|
|
;============
|
|
; 13
|
|
|
|
mb_play_music:
|
|
|
|
|
|
;======================================
|
|
; Write frames to Mockingboard
|
|
;======================================
|
|
; actually plays frame loaded at end of
|
|
; last interrupt, so 20ms behind?
|
|
|
|
mb_write_frame:
|
|
|
|
|
|
ldx #0 ; set up reg count ; 2
|
|
;============
|
|
; 2
|
|
|
|
;==================================
|
|
; loop through the 14 registers
|
|
; reading the value, then write out
|
|
;==================================
|
|
; inlined "write_ay_both" to save up to 156 (12*13) cycles
|
|
; unrolled
|
|
|
|
mb_write_loop:
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
cmp REGISTER_OLD,X ; compare with old values ; 4
|
|
beq mb_no_write ; 3/2nt
|
|
;=============
|
|
; typ 11
|
|
|
|
; special case R13. If it is 0xff, then don't update
|
|
; otherwise might spuriously reset the envelope settings
|
|
|
|
cpx #13 ; 2
|
|
bne mb_not_13 ; 3/2nt
|
|
cmp #$ff ; 2
|
|
beq mb_skip_13 ; 3/2nt
|
|
;============
|
|
; typ 5
|
|
mb_not_13:
|
|
|
|
|
|
; address
|
|
stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
|
|
; value
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
|
|
mb_no_write:
|
|
inx ; point to next register ; 2
|
|
cpx #14 ; if 14 we're done ; 2
|
|
bmi mb_write_loop ; otherwise, loop ; 3/2nt
|
|
;============
|
|
; 7
|
|
mb_skip_13:
|
|
|
|
|
|
;=====================================
|
|
; Copy registers to old
|
|
;=====================================
|
|
ldx #13 ; 2
|
|
mb_reg_copy:
|
|
lda REGISTER_DUMP,X ; load register value ; 4
|
|
sta REGISTER_OLD,X ; compare with old values ; 4
|
|
dex ; 2
|
|
bpl mb_reg_copy ; 2nt/3
|
|
;=============
|
|
; 171
|
|
|
|
|
|
;======================================
|
|
; Write frames to Mockingboard
|
|
;======================================
|
|
; actually plays frame loaded at end of
|
|
; last interrupt, so 20ms behind?
|
|
|
|
mb_write_frame2:
|
|
|
|
|
|
ldx #0 ; set up reg count ; 2
|
|
;============
|
|
; 2
|
|
mb_write_loop2:
|
|
lda REGISTER_DUMP2,X ; load register value ; 4
|
|
cmp REGISTER_OLD2,X ; compare with old values ; 4
|
|
beq mb_no_write2 ; 3/2nt
|
|
;=============
|
|
; typ 11
|
|
|
|
; special case R13. If it is 0xff, then don't update
|
|
; otherwise might spuriously reset the envelope settings
|
|
|
|
cpx #13 ; 2
|
|
bne mb_not_132 ; 3/2nt
|
|
cmp #$ff ; 2
|
|
beq mb_skip_132 ; 3/2nt
|
|
;============
|
|
; typ 5
|
|
mb_not_132:
|
|
|
|
|
|
; address
|
|
stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
lda REGISTER_DUMP2,X ; load register value ; 4
|
|
sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB2 ; 4
|
|
|
|
mb_no_write2:
|
|
inx ; point to next register ; 2
|
|
cpx #14 ; if 14 we're done ; 2
|
|
bmi mb_write_loop2 ; otherwise, loop ; 3/2nt
|
|
;============
|
|
; 7
|
|
mb_skip_132:
|
|
|
|
|
|
;=====================================
|
|
; Copy registers to old
|
|
;=====================================
|
|
ldx #13 ; 2
|
|
mb_reg_copy2:
|
|
lda REGISTER_DUMP2,X ; load register value ; 4
|
|
sta REGISTER_OLD2,X ; compare with old values ; 4
|
|
dex ; 2
|
|
bpl mb_reg_copy2 ; 2nt/3
|
|
;=============
|
|
; 171
|
|
|
|
|
|
;===================================
|
|
; Load all 14 registers in advance
|
|
;===================================
|
|
; note, assuming not cross page boundary, not any slower
|
|
; then loading from zero page?
|
|
|
|
mb_load_values:
|
|
|
|
ldx #0 ; set up reg count ; 2
|
|
ldy MB_CHUNK_OFFSET ; get chunk offset ; 3
|
|
;=============
|
|
; 5
|
|
|
|
mb_load_loop:
|
|
lda (INL),y ; load register value ; 5
|
|
sta REGISTER_DUMP,X ; 4
|
|
lda (INL2),y
|
|
sta REGISTER_DUMP2,X
|
|
;============
|
|
; 9
|
|
;====================
|
|
; point to next page
|
|
;====================
|
|
|
|
clc ; point to next interleaved ; 2
|
|
lda INH ; page by adding CHUNKSIZE (3/1); 3
|
|
adc CHUNKSIZE ; 3
|
|
sta INH ; 3
|
|
|
|
clc
|
|
lda INH2
|
|
adc CHUNKSIZE
|
|
sta INH2
|
|
|
|
inx ; point to next register ; 2
|
|
cpx #14 ; if 14 we're done ; 2
|
|
bmi mb_load_loop ; otherwise, loop ; 3/2nt
|
|
;============
|
|
; 18
|
|
|
|
;=========================================
|
|
; if A_COARSE_TONE is $ff then we are done
|
|
|
|
lda A_COARSE_TONE ; 3
|
|
bpl mb_not_done ; 3/2nt
|
|
|
|
lda #1 ; set done playing ; 2
|
|
|
|
jmp quiet_exit ; 3
|
|
;===========
|
|
; typ 6
|
|
mb_not_done:
|
|
|
|
;==============================================
|
|
; incremement offset. If 0 move to next chunk
|
|
;==============================================
|
|
|
|
increment_offset:
|
|
|
|
inc MB_CHUNK_OFFSET ; increment offset ; 5
|
|
bne back_to_first_reg ; if not zero, done ; 3/2nt
|
|
|
|
|
|
;=====================
|
|
; move to next state
|
|
;=====================
|
|
|
|
clc
|
|
rol DECODER_STATE ; next state ; 5
|
|
; 20 -> 40 -> 80 -> c+00
|
|
bcs wraparound_to_a ; 3/2nt
|
|
|
|
bit DECODER_STATE ;bit7->N bit6->V
|
|
bvs back_to_first_reg ; do nothing on B ; 3/2nt
|
|
|
|
start_c:
|
|
lda #1
|
|
sta CHUNKSIZE
|
|
|
|
; setup next three chunks of song
|
|
|
|
lda #1 ; start decompressing
|
|
sta DECOMPRESS_TIME ; outside of handler
|
|
|
|
jmp back_to_first_reg
|
|
|
|
wraparound_to_a:
|
|
lda #$3
|
|
sta CHUNKSIZE
|
|
lda #$20
|
|
sta DECODER_STATE
|
|
sta COPY_TIME ; start copying
|
|
|
|
lda DECOMPRESS_TIME ; Trouble if decompressing
|
|
beq blah ; takes too long?
|
|
lda #1
|
|
sta DECODE_ERROR
|
|
blah:
|
|
;==============================
|
|
; After 14th reg, reset back to
|
|
; read R0 data
|
|
;==============================
|
|
|
|
back_to_first_reg:
|
|
lda #0 ; 2
|
|
bit DECODER_STATE ; 3
|
|
bmi back_to_first_reg_c ; 2nt/3
|
|
bvc back_to_first_reg_a ; 2nt/3
|
|
|
|
back_to_first_reg_b:
|
|
lda #$1 ; offset by 1
|
|
|
|
back_to_first_reg_a:
|
|
clc ; 2
|
|
adc #>UNPACK_BUFFER1 ; in proper chunk 1 or 2; 2
|
|
sta INH ; update r0 pointer ; 3
|
|
sec
|
|
sbc #>UNPACK_BUFFER1
|
|
clc
|
|
adc #>UNPACK_BUFFER2
|
|
sta INH2
|
|
|
|
jmp update_r0_pointer ; 3
|
|
|
|
back_to_first_reg_c:
|
|
lda #>(UNPACK_BUFFER1+$2A00) ; in linear C area ; 2
|
|
sta INH ; update r0 pointer ; 3
|
|
lda #>(UNPACK_BUFFER2+$2A00) ; in linear C area ; 2
|
|
sta INH2 ; update r0 pointer ; 3
|
|
|
|
update_r0_pointer:
|
|
|
|
|
|
|
|
|
|
;=================================
|
|
; Finally done with this interrupt
|
|
;=================================
|
|
|
|
done_interrupt:
|
|
|
|
|
|
;=====================
|
|
; Update time counter
|
|
;=====================
|
|
update_time:
|
|
inc FRAME_COUNT ; 5
|
|
lda FRAME_COUNT ; 3
|
|
cmp #50 ; 3
|
|
bne done_time ; 3/2nt
|
|
|
|
lda #$0 ; 2
|
|
sta FRAME_COUNT ; 3
|
|
|
|
update_second_ones:
|
|
inc $7d0+TIME_OFFSET+3 ; 6
|
|
inc $bd0+TIME_OFFSET+3 ; 6
|
|
lda $bd0+TIME_OFFSET+3 ; 4
|
|
cmp #$ba ; one past '9' ; 2
|
|
bne done_time ; 3/2nt
|
|
lda #'0'+$80 ; 2
|
|
sta $7d0+TIME_OFFSET+3 ; 4
|
|
sta $bd0+TIME_OFFSET+3 ; 4
|
|
update_second_tens:
|
|
inc $7d0+TIME_OFFSET+2 ; 6
|
|
inc $bd0+TIME_OFFSET+2 ; 6
|
|
lda $bd0+TIME_OFFSET+2 ; 4
|
|
cmp #$b6 ; 6 (for 60 seconds) ; 2
|
|
bne done_time ; 3/2nt
|
|
lda #'0'+$80 ; 2
|
|
sta $7d0+TIME_OFFSET+2 ; 4
|
|
sta $bd0+TIME_OFFSET+2 ; 4
|
|
update_minutes:
|
|
inc $7d0+TIME_OFFSET ; 6
|
|
inc $bd0+TIME_OFFSET ; 6
|
|
; we don't handle > 9:59 songs yet
|
|
done_time:
|
|
;=============
|
|
; 90 worst
|
|
|
|
|
|
;=================================
|
|
; Moved visualization here as a hack
|
|
;=================================
|
|
|
|
;============================
|
|
; Visualization
|
|
;============================
|
|
|
|
jsr clear_top
|
|
lda RASTERBARS_ON
|
|
beq skip_rasters
|
|
jsr draw_rasters
|
|
skip_rasters:
|
|
jsr volume_bars
|
|
jsr page_flip
|
|
|
|
|
|
check_keyboard:
|
|
|
|
jsr get_key
|
|
lda LASTKEY
|
|
beq exit_interrupt
|
|
|
|
cmp #(' '+$80)
|
|
bne key_R
|
|
key_space:
|
|
lda #$80
|
|
eor DONE_PLAYING
|
|
jmp quiet_exit
|
|
|
|
key_R:
|
|
cmp #'R'
|
|
bne key_left
|
|
|
|
lda #$ff
|
|
eor RASTERBARS_ON
|
|
sta RASTERBARS_ON
|
|
jmp done_key
|
|
|
|
key_left:
|
|
cmp #'A'
|
|
bne key_right
|
|
|
|
lda #$40
|
|
bne quiet_exit
|
|
|
|
key_right:
|
|
cmp #'D'
|
|
bne done_key
|
|
|
|
lda #$20
|
|
bne quiet_exit
|
|
|
|
done_key:
|
|
jmp exit_interrupt
|
|
|
|
quiet_exit:
|
|
sta DONE_PLAYING
|
|
jsr clear_ay_both
|
|
|
|
;=====================================
|
|
; clear register area
|
|
;=====================================
|
|
ldx #13 ; 2
|
|
lda #0 ; 2
|
|
mb_clear_reg:
|
|
sta REGISTER_DUMP,X ; clear register value ; 4
|
|
sta REGISTER_OLD,X ; clear old values ; 4
|
|
sta REGISTER_DUMP2,X ; clear register value ; 4
|
|
sta REGISTER_OLD2,X ; clear old values ; 4
|
|
dex ; 2
|
|
bpl mb_clear_reg ; 2nt/3
|
|
|
|
exit_interrupt:
|
|
|
|
; pla ; restore a ; 4
|
|
|
|
pla
|
|
tay ; restore Y
|
|
pla
|
|
tax ; restore X
|
|
lda $45 ; restore A
|
|
|
|
|
|
rti ; return from interrupt ; 6
|
|
|
|
;============
|
|
; typical
|
|
; ???? cycles
|
|
|
|
|
|
REGISTER_OLD:
|
|
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0
|
|
|
|
REGISTER_OLD2:
|
|
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0
|