From: "Andrew Davidson" Newsgroups: comp.os.msdos.djgpp Subject: Re: Fast reading of multiple keypresses in Allegro Date: Fri, 19 Feb 1999 20:44:14 -0000 Organization: Customer of Planet Online Lines: 32 Message-ID: <7akim8$1k6$1@news5.svr.pol.co.uk> References: <8D53104ECD0CD211AF4000A0C9D60AE356734A AT probe-2 DOT acclaim-euro DOT net> NNTP-Posting-Host: modem-65.technetium.dialup.pol.co.uk X-Trace: news5.svr.pol.co.uk 919457288 1670 62.136.21.65 (19 Feb 1999 20:48:08 GMT) NNTP-Posting-Date: 19 Feb 1999 20:48:08 GMT X-Complaints-To: abuse AT theplanet DOT net X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.0810.800 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.0810.800 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Shawn Hargreaves wrote in message news:8D53104ECD0CD211AF4000A0C9D60AE356734A AT probe-2 DOT acclaim-euro DOT net... >Andrew Davidson writes: >> I think I'm approaching this problem from the wrong angle. Rather >> than play a sample through allegro's functions is there any way I >> can simply flex or relax the speakers a single time? > >The SB does have a non-DMA mode where you can just write sample >values to the DAC whenever you feel like it, but I don't think >this will really do what you want (so what exactly do you want, >anyway? It would be useful if you could describe your goal in >a bit more detail :-) Modern soundcards are designed for playing >streams of sample data at a constant rate, and I think you will >have a lot of trouble coaxing them to emulate those old speaker >effects. I'm actually after emulating the tv speaker connected to a Spectrum computer which was activated using bit 4 of port 254. The speaker flexes if bit 4 is a 1 and relaxes if bit 4 is a 0. I need to do this in real time to tie in with the rest of the emulation. >If you want to generate a waveform on the fly, you can use the >Allegro audio streaming functions, as demonstrated in ex28.c. Would this be capable of playing real time music and sound effects generated by flexing/relaxing a speaker at differing frequencies? I'll have to have a look at this. Andrew