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some documentation fixes

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This commit is contained in:
Christian Groessler 2023-01-18 11:55:52 +01:00
parent dbefd12571
commit 60f56c43c7
2 changed files with 11 additions and 6 deletions
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11
doc/funcref.sgml
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@ -1114,18 +1114,21 @@ considered random to a certain degree.
<descrip>
<tag/Function/Use the speaker to produce sound in a specified voice. (Atari only)
<tag/Header/<tt/<ref id="atari.h" name="atari.h">/
<tag/Declaration/<tt/void _sound (unsigned char voice, unsigned char pitch, unsigned char distortion, unsigned char volume);/
<tag/Description/The function produces a sound with the specified parameters. using any of the 4 availble oscillators (voices) controlled by POKEY chip. Sound is non cpu-blocking and it keeps oscillating until program sends 0 in all the other parameters.
<tag/Declaration/<tt/void __fastcall__ _sound (unsigned char voice, unsigned char pitch, unsigned char distortion, unsigned char volume);/
<tag/Description/The function produces a sound with the specified parameters using any of the 4 available oscillators (voices) controlled by the POKEY chip. Sound is non cpu-blocking and it keeps oscillating until program sends 0 in all the other parameters.
<tag/Notes/<itemize>
<item>The function is available only as a fastcall function; so, it may be used
only in the presence of a prototype.
<item>The function is specific to the Atari 8 bit.
<item> Voice can be any of 0-3 different sound channels.
<item> Pitch goes from 0-255 (about 125 Hz to 32 Khz).
<item> Distortion (0-14) uses poly dividers to reshape wave in order to create a noise effect. Use 10 for a "pure" square-wave sound.
<item>Volume (0-15) is the intensity for the wave.
<item>Extra bits in those parameters will be ignored.
<item>Parameters are the same as for the AtariBASIC SOUND statement.
</itemize>
<tag/Availability/cc65 (not all platforms)
<tag/Availability/cc65 (<tt/atari/ and <tt/atarixl/ platforms)
<tag/Example/
<verb>
@ -4186,7 +4189,7 @@ be used in presence of a prototype.
<tag/Example/<verb>
chdir (getdevicedir (device, buf, sizeof buf));
</verb>
cf. <tt/samples/enumdevdir.c/
cf. <tt/samples&sol;enumdevdir.c/
</descrip>
</quote>

6
libsrc/atari/sound.s
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@ -2,14 +2,16 @@
; Mariano Domínguez
; 2022-12-4
;
; atari lib
; this file provides an equivalent to the BASIC SOUND function
;
; void __fastcall__ _sound (unsigned char voice, unsigned char frequency, unsigned char distortion, unsigned char volume);
;
.include "atari.inc"
.export __sound
.import popa
.importzp tmp1,tmp2
; play sound, arguments: voice, pitch, distortion, volume. same as BASIC
; play sound, arguments: voice, pitch, distortion, volume
.proc __sound
sta tmp2 ;save volume
jsr popa ;get distortion