dos33fsprogs/pt3_player/pt3_timer.s

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; PT3 Timer -- times how long it takes
.include "zp.inc"
.include "hardware.inc"
PT3_LOC = $4000
PT3_USE_ZERO_PAGE = 1
;=============================
; Setup
;=============================
pt3_setup:
jsr HOME
jsr TEXT
; Init disk code
jsr rts_init
; init variables
lda #0
sta DRAW_PAGE
sta DONE_PLAYING
sta WHICH_FILE
jsr mockingboard_detect_slot4 ; call detection routine
cpx #$1
beq mockingboard_found
mockingboard_found:
;============================
; Init the Mockingboard
;============================
jsr mockingboard_init
jsr reset_ay_both
jsr clear_ay_both
;=========================
; Setup Interrupt Handler
;=========================
; Vector address goes to 0x3fe/0x3ff
; FIXME: should chain any existing handler
lda #<interrupt_handler
sta $03fe
lda #>interrupt_handler
sta $03ff
;============================
; Enable 50Hz clock on 6522
;============================
sei ; disable interrupts just in case
lda #$40 ; Continuous interrupts, don't touch PB7
sta $C40B ; ACR register
lda #$7F ; clear all interrupt flags
sta $C40E ; IER register (interrupt enable)
lda #$C0
sta $C40D ; IFR: 1100, enable interrupt on timer one oflow
sta $C40E ; IER: 1100, enable timer one interrupt
lda #$E7
sta $C404 ; write into low-order latch
lda #$4f
sta $C405 ; write into high-order latch,
; load both values into counter
; clear interrupt and start counting
; 4fe7 / 1e6 = .020s, 50Hz
;==================
; load first song
;==================
jsr new_song
;============================
; Enable 6502 interrupts
;============================
cli ; clear interrupt mask
;============================
; Loop forever
;============================
main_loop:
; play song as fast as possible
jsr interrupt_simulator
check_done:
lda #$ff
bit DONE_PLAYING
beq main_loop ; if was all zeros, loop
; right pressed
done_play:
sei ; disable interrupts
; print results
jsr CROUT
jsr CROUT
lda timer_seconds_h
jsr PRBYTE
lda timer_seconds_l
jsr PRBYTE
lda #'.'+$80
jsr COUT
lda timer_fractions
jsr PRBYTE
jsr CROUT
jsr CROUT
lda #0
sta DONE_PLAYING
forever_loop:
jmp forever_loop
;=================
; load a new song
;=================
new_song:
;=========================
; Init Variables
;=========================
; ?
;===========================
; Load in PT3 file
;===========================
jsr get_filename
; needs to be space-padded $A0 30-byte filename
lda #<readfile_filename
sta namlo
lda #>readfile_filename
sta namhi
ldy #0
ldx #30 ; 30 chars
name_loop:
lda (INL),Y
beq space_loop
ora #$80
sta (namlo),Y
iny
dex
bne name_loop
beq done_name_loop
space_loop:
lda #$a0 ; pad with ' '
sta (namlo),Y
iny
dex
bne space_loop
done_name_loop:
; open and read a file
; loads to whatever it was BSAVED at (default is $2000)
jsr read_file ; read PT3 file from disk
;=========================
; Print Info
;=========================
; re-init, as we've run through it
lda #0
sta DONE_PLAYING
jsr pt3_init_song
rts
;==================
; Get filename
;==================
; WHICH_FILE holds number
; MAX_FILES has max
; Scroll through until find
; point INH:INL to it
get_filename:
ldy #0
ldx WHICH_FILE
lda #<song_list ; point to filename
sta INL
lda #>song_list
sta INH
get_filename_loop:
cpx #0
beq filename_found
inner_loop:
iny
lda (INL),Y
bne inner_loop
iny
dex
jmp get_filename_loop
filename_found:
tya
clc
adc INL
sta INL
lda INH
adc #0
sta INH
rts
;==========
; filenames
;==========
song_list:
.asciiz "SR.PT3"
;=========
;routines
;=========
.include "mockingboard_a.s"
.include "qkumba_rts.s"
.include "pt3_lib_core.s"
.include "pt3_lib_init.s"
timer_fractions: .byte $0
timer_seconds_l: .byte $0
timer_seconds_h: .byte $0
;======================================
; simply time things with a 50Hz clock
interrupt_handler:
; pha ; save A ; 3
; A is saved in $45 by firmware
txa
pha ; save X
tya
pha ; save Y
bit $C404 ; clear 6522 interrupt by reading T1C-L ; 4
count_time:
inc timer_fractions
lda timer_fractions
cmp #50 ; 50Hz
bne done_count_time
lda #$0
sta timer_fractions
inc timer_seconds_l
bne done_count_time
inc timer_seconds_h
done_count_time:
exit_interrupt_handler:
; pla ; restore a ; 4
pla
tay ; restore Y
pla
tax ; restore X
lda $45 ; restore A
rti ; return from interrupt ; 6
interrupt_simulator:
; pha ; save A ; 3
; A is saved in $45 by firmware
txa
pha ; save X
tya
pha ; save Y
; bit $C404 ; clear 6522 interrupt by reading T1C-L ; 4
bit $1234
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:
jsr pt3_make_frame
lda DONE_SONG
beq mb_write_frame
lda #$20
jmp quiet_exit
;======================================
; Write frames to Mockingboard
;======================================
; actually plays frame loaded at end of
; last interrupt, so 20ms behind?
mb_write_frame:
ldx #0 ; set up reg count ; 2
;============
; 2
;==================================
; loop through the 14 registers
; reading the value, then write out
;==================================
mb_write_loop:
lda AY_REGISTERS,X ; load register value ; 4
; special case R13. If it is 0xff, then don't update
; otherwise might spuriously reset the envelope settings
cpx #13 ; 2
bne mb_not_13 ; 3/2nt
cmp #$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
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ldy #MOCK_AY_INACTIVE ; go inactive ; 2
sty MOCK_6522_ORB1 ; 4
sty 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
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sty MOCK_6522_ORB1 ; 4
sty MOCK_6522_ORB2 ; 4
;===========
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; 60
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:
done_time:
check_keyboard:
jmp exit_interrupt
quiet_exit:
sta DONE_PLAYING
jsr clear_ay_both
exit_interrupt:
; pla ; restore a ; 4
pla
tay ; restore Y
pla
tax ; restore X
lda $45 ; restore A
rts ; return from interrupt ; 6
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;============
; dummy vars
;============
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pt3_loop_smc: