dos33fsprogs/games/peasant/ssi263_simple_speech.s
Vince Weaver b1eac20e68 peasant: update ssi sound, also fix problem with stereo
music stopped being stereo in ending as we weren't resetting
the 6522s enough after doing text
2021-10-03 23:03:49 -04:00

273 lines
4.3 KiB
ArmAsm

.include "ssi263.inc"
; Simple speech routine for ssi-263
; to save space we only change the Phoneme/Delay each time, we don't
; mess with the other registers
;========================
; ssi263_write_chip
;========================
ssi263_write_chip:
wc_smc1:
sta $C000,X
rts
;========================
; read_chip
;========================
ssi263_read_chip:
rc_smc1:
lda $C000,X
rts
;========================
; ssi263_speech_init
;========================
; A = slot number of mockingboard
ssi263_speech_init:
sei ; disable interrupts
lda MOCKINGBOARD_SLOT
and #$7
ora #$c0 ; turn slot number into address
sta wc_smc1+2 ; update the read/write routines
sta rc_smc1+2
; Set 6522#2 peripheral control register to recognize the signal
; from the speech chip.
lda #(VIA6522_PCR2_CA2_LOW|VIA6522_PCR2_CA1_NEG)
ldx #VIA6522_PCR2
jsr ssi263_write_chip
lda #<ssi263_speech_irq ; point IRQ handler to our code
sta $fffe
lda #>ssi263_speech_irq
sta $ffff
; set defaults
; filter frequency
; lda #$E9
; ldx #SSI263_F
; jsr ssi263_write_chip
; control / articulation/ amplitude
; lda #$5C
; ldx #SSI263_CAA
; jsr ssi263_write_chip
; rate/inflection
; lda #$A8
; ldx #SSI263_RI
; jsr ssi263_write_chip
; inflection
; lda #$50
; ldx #SSI263_I
; jsr ssi263_write_chip
cli ; enable interrupts
rts
;============================
; ssi263_speech_shutdown
;============================
ssi263_speech_shutdown:
sei
jsr ssi263_disable
rts
;=========================
; ssi263_speak
;=========================
; pointer to data in SPEECH_PTRL/H
ssi263_speak:
sei ; disable interrupts
; Set the busy flag
lda #$FF
sta speech_busy
; Set peripheral control register to recognize the signal from the
; speech chip.
lda #(VIA6522_PCR2_CA2_LOW|VIA6522_PCR2_CA1_NEG)
ldx #VIA6522_PCR2
jsr ssi263_write_chip
; Set transitioned inflection by setting value while toggling CTL
lda #SSI263_CAA_CTL
ldx #SSI263_CAA
jsr ssi263_write_chip
; Set transitioned inflection mode in register 0
lda #SSI263_DRP_TRANSITIONED_INFLECTION
ldx #SSI263_DRP
jsr ssi263_write_chip
; Lower control bit
lda #$70 ; also T=7
ldx #SSI263_CAA
jsr ssi263_write_chip
; Enable 6522 interrupts
lda #(VIA6522_IER2_SET|VIA6522_IER2_CA1)
ldx #VIA6522_IER2
jsr ssi263_write_chip
cli ; re-enable interrupts
rts
;====================
; speech interrupt
;====================
ssi263_speech_irq:
php ; save flags
cld
pha ; save A
txa
pha ; save X
tya
pha ; save Y
; inc $0404 ; irq indicator on screen
; be sure it was a 6522#2 interrupt
ldx #VIA6522_IFR2
jsr ssi263_read_chip
bmi have_interrupt
; wasn't us, return to caller
; this assumes we can handle multiple interrupt sources
jmp end_interrupt
have_interrupt:
; Clear the 6522#2 CA interrupt flag
lda #VIA6522_IFR2_CA1
ldx #VIA6522_IFR2
jsr ssi263_write_chip
; Check if done with speech
ldy #0
lda (SPEECH_PTRL),Y
cmp #$ff
beq speech_end
not_end:
; Set the speech playing flag
lda #$ff
sta speech_playing
ldy #$00
; Get the next data
lda (SPEECH_PTRL),Y
ldx #SSI263_DRP ; duration/phoneme
jsr ssi263_write_chip
; filter frequency
lda #$E9
ldx #SSI263_F
jsr ssi263_write_chip
; control / articulation/ amplitude
lda #$5C
ldx #SSI263_CAA
jsr ssi263_write_chip
; rate/inflection
lda #$A8
ldx #SSI263_RI
jsr ssi263_write_chip
; inflection
lda #$50
ldx #SSI263_I
jsr ssi263_write_chip
; Next data (inc 16 bit)
inc SPEECH_PTRL
bne no_oflo
inc SPEECH_PTRH
no_oflo:
; Finish the interrupt handler
jmp end_interrupt
speech_end:
jsr ssi263_disable
end_interrupt:
pla
tay ; restore Y
pla
tax ; restore X
pla ; restore A
interrupt_smc:
; lda $45 ; restore A (II+/IIe)
plp ; restore flags
rti ; return from interrupt
ssi263_disable:
; If at the end, turn everything off
; Toggle CTL while DR set to disable A/!R
lda #SSI263_CAA_CTL
ldx #SSI263_CAA
jsr ssi263_write_chip
lda #SSI263_DRP_DISABLE_AR
ldx #SSI263_DRP
jsr ssi263_write_chip
; Zero amplitude
lda #$70
ldx #SSI263_CAA
jsr ssi263_write_chip
; Clear busy and playing flags
lda #$00
sta speech_busy
sta speech_playing
; Disable interrupt in 6522
lda #VIA6522_IER2_CA1
ldx #VIA6522_IER2
jsr ssi263_write_chip
rts
speech_busy: .byte $00
speech_playing: .byte $00