mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-06 03:04:43 +00:00
315 lines
5.7 KiB
ArmAsm
315 lines
5.7 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 pt3_play_music ; if song done, don't play music ; 3/2nt
|
|
jmp check_keyboard ; 3
|
|
;============
|
|
; 13
|
|
|
|
pt3_play_music:
|
|
|
|
; decode a frame of music
|
|
|
|
jsr pt3_make_frame
|
|
|
|
; handle song over condition
|
|
lda DONE_SONG
|
|
beq mb_write_frame ; if not done, continue
|
|
|
|
lda LOOP ; see if looping
|
|
beq move_to_next
|
|
|
|
lda pt3_loop ; looping, move to loop location
|
|
sta current_pattern
|
|
lda #$0
|
|
sta current_line
|
|
sta current_subframe
|
|
sta DONE_SONG ; undo the next song
|
|
|
|
jmp done_interrupt
|
|
|
|
move_to_next:
|
|
; same as "press right"
|
|
lda #$20
|
|
jmp quiet_exit
|
|
|
|
;======================================
|
|
; Write frames to Mockingboard
|
|
;======================================
|
|
; for speed could merge this into
|
|
; the decode code
|
|
|
|
mb_write_frame:
|
|
|
|
|
|
ldx #0 ; set up reg count ; 2
|
|
;============
|
|
; 2
|
|
|
|
;==================================
|
|
; loop through the 14 registers
|
|
; reading the value, then write out
|
|
;==================================
|
|
|
|
mb_write_loop:
|
|
lda AY_REGISTERS,X ; load register value ; 4
|
|
|
|
; special case R13. If it is 0xff, then don't update
|
|
; otherwise might spuriously reset the envelope settings
|
|
|
|
cpx #13 ; 2
|
|
bne mb_not_13 ; 3/2nt
|
|
cmp #$ff ; 2
|
|
beq mb_skip_13 ; 3/2nt
|
|
;============
|
|
; typ 5
|
|
mb_not_13:
|
|
|
|
|
|
; address
|
|
stx MOCK_6522_ORA1 ; put address on PA1 ; 4
|
|
stx MOCK_6522_ORA2 ; put address on PA2 ; 4
|
|
lda #MOCK_AY_LATCH_ADDR ; latch_address for PB1 ; 2
|
|
sta MOCK_6522_ORB1 ; latch_address on PB1 ; 4
|
|
sta MOCK_6522_ORB2 ; latch_address on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
sta MOCK_6522_ORB2 ; 4
|
|
|
|
; value
|
|
lda AY_REGISTERS,X ; load register value ; 4
|
|
sta MOCK_6522_ORA1 ; put value on PA1 ; 4
|
|
sta MOCK_6522_ORA2 ; put value on PA2 ; 4
|
|
lda #MOCK_AY_WRITE ; ; 2
|
|
sta MOCK_6522_ORB1 ; write on PB1 ; 4
|
|
sta MOCK_6522_ORB2 ; write on PB2 ; 4
|
|
lda #MOCK_AY_INACTIVE ; go inactive ; 2
|
|
sta MOCK_6522_ORB1 ; 4
|
|
sta MOCK_6522_ORB2 ; 4
|
|
;===========
|
|
; 62
|
|
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:
|
|
|
|
|
|
;=================================
|
|
; Finally done with this interrupt
|
|
;=================================
|
|
|
|
done_interrupt:
|
|
|
|
|
|
;=====================
|
|
; Update time counter
|
|
;=====================
|
|
; self-modifying version via qkumba
|
|
update_time:
|
|
inc frame_count_smc+1 ; 5
|
|
frame_count_smc:
|
|
lda #$0 ; 2
|
|
cmp #50 ; 3
|
|
bne done_time ; 3/2nt
|
|
|
|
lda #$0 ; 2
|
|
sta frame_count_smc+1 ; 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:
|
|
;=============
|
|
; 89 worst
|
|
|
|
|
|
;=================================
|
|
; Handle keyboard
|
|
;=================================
|
|
|
|
check_keyboard:
|
|
|
|
jsr get_key
|
|
lda LASTKEY
|
|
beq exit_interrupt
|
|
|
|
;====================
|
|
; space pauses
|
|
|
|
cmp #(' '+$80)
|
|
bne key_M
|
|
key_space:
|
|
lda #$80
|
|
eor DONE_PLAYING
|
|
|
|
; disable fire when paused
|
|
|
|
sta DONE_PLAYING
|
|
beq yes_bar
|
|
lda #0
|
|
jmp lowbar
|
|
yes_bar:
|
|
lda #7
|
|
lowbar:
|
|
jsr fire_setline
|
|
|
|
lda DONE_PLAYING
|
|
|
|
jmp quiet_exit
|
|
|
|
;===========================
|
|
; M key switches MHz mode
|
|
|
|
key_M:
|
|
cmp #'M'
|
|
bne key_L
|
|
|
|
lda convert_177
|
|
eor #$1
|
|
sta convert_177
|
|
beq at_1MHz
|
|
|
|
; update text on screen
|
|
|
|
lda #'7'+$80
|
|
sta $7F4
|
|
sta $BF4
|
|
jmp done_key
|
|
|
|
at_1MHz:
|
|
lda #'0'+$80
|
|
sta $7F4
|
|
sta $BF4
|
|
|
|
jmp done_key
|
|
|
|
|
|
;===========================
|
|
; L enables loop mode
|
|
|
|
key_L:
|
|
cmp #'L'
|
|
bne key_left
|
|
|
|
lda LOOP
|
|
eor #$1
|
|
sta LOOP
|
|
beq music_looping
|
|
|
|
; update text on screen
|
|
|
|
lda #'L'+$80
|
|
sta $7D0+18
|
|
sta $BD0+18
|
|
jmp done_key
|
|
|
|
music_looping:
|
|
lda #'/'+$80
|
|
sta $7D0+18
|
|
sta $BD0+18
|
|
|
|
jmp done_key
|
|
|
|
|
|
;======================
|
|
; left key, to prev song
|
|
|
|
key_left:
|
|
cmp #'A'
|
|
bne key_right
|
|
|
|
lda #$40
|
|
bne quiet_exit
|
|
|
|
;========================
|
|
; right key, to next song
|
|
|
|
key_right:
|
|
cmp #'D'
|
|
bne done_key
|
|
|
|
lda #$20
|
|
bne quiet_exit
|
|
|
|
done_key:
|
|
jmp exit_interrupt
|
|
|
|
;========================
|
|
; stop playing for now
|
|
; quiet down the Mockingboard
|
|
; (otherwise will be stuck on last note)
|
|
|
|
quiet_exit:
|
|
sta DONE_PLAYING
|
|
jsr clear_ay_both
|
|
|
|
lda #$ff ; also mute the channel
|
|
sta AY_REGISTERS+7 ; just in case
|
|
|
|
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
|
|
|
|
|