74 lines
1.9 KiB
NASM
74 lines
1.9 KiB
NASM
; TI SN76489 sound chip driver
|
|
; @author Daniele Verducci
|
|
; @language: Z80 ASM
|
|
;
|
|
;
|
|
; This file is part of Pat80 Memory Monitor.
|
|
;
|
|
; Pat80 Memory Monitor is free software: you can redistribute it and/or modify
|
|
; it under the terms of the GNU General Public License as published by
|
|
; the Free Software Foundation, either version 3 of the License, or
|
|
; (at your option) any later version.
|
|
;
|
|
; Pat80 Memory Monitor is distributed in the hope that it will be useful,
|
|
; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
; GNU General Public License for more details.
|
|
;
|
|
; You should have received a copy of the GNU General Public License
|
|
; along with Pat80 Memory Monitor. If not, see <http://www.gnu.org/licenses/>.
|
|
;
|
|
;
|
|
; USAGE:
|
|
; call Snd_init <-- inits sound (and silences default tone)
|
|
; call Snd_beep <-- system beep
|
|
|
|
; Sound card is on port 1
|
|
SND_DATA_REG: EQU IO_1
|
|
|
|
; Init device (silence all channels)
|
|
; Bits meaning:
|
|
; 1 R0 R1 R2 A0 A1 A2 A3
|
|
; Bit0 is 1
|
|
; Bit1,2,3 select the channel: 001, 011, 101, 111(noise)
|
|
; Bit4,5,6,7 selecy the attenuation (0000=full volume, 1111=silent)
|
|
Snd_init:
|
|
; silence ch1
|
|
ld a,%10011111
|
|
out (SND_DATA_REG),a
|
|
; silence ch2
|
|
ld a,%10111111
|
|
out (SND_DATA_REG),a
|
|
; silence ch3
|
|
ld a,%11011111
|
|
out (SND_DATA_REG),a
|
|
; silence noise ch
|
|
ld a,%11111111
|
|
out (SND_DATA_REG),a
|
|
ret
|
|
|
|
; Plays the system beep.
|
|
Snd_beep:
|
|
; ch1 max volume
|
|
ld a,%10010000
|
|
out (SND_DATA_REG),a
|
|
; play beep freq
|
|
ld a,%10000000
|
|
out (SND_DATA_REG),a
|
|
ld a,%00001000
|
|
out (SND_DATA_REG),a
|
|
; wait
|
|
ld bc, (TIME_DUR_MILLIS * 10)
|
|
call Time_delay55
|
|
; silence ch1
|
|
ld a,%10011111
|
|
out (SND_DATA_REG),a
|
|
ret
|
|
|
|
; Sets the attenuation value for a channel
|
|
; @param a Channel (0, 1, 2, 3(Noise))
|
|
; @param c Attenuation (0 to 16)
|
|
; Snd_setAtt:
|
|
; cp a, 0
|
|
|