Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.os.msdos.programmer > #4183

Re: is there a high-frequency timer available on the PC? (besides the PIT)

Show all headers | View raw

2022-08-19 at 19:44 -0000, Ross Ridge wrote:
> Digging a little deaper, while Windows 9x does let MS-DOS applications
> change the PIT timer interval, it doesn't let you set a timer
> frequency faster than 1 kHz.

Not very useful for audio generation. :)

> Anything else is likey to not work on Windows and/or not as as wide of
> a range of hardware as the PIT or TSC.

Thanks, that's indeed what I think as well. I was silently hoping for
some exotic "under the hood" tricks like "reading port x or y takes
between 33-37 microseconds on all PCs" or something alike. Yes, wishful
thinking, I know.

I did some archaeology and it appears that so far whenever people
wanted or needed to generate real-time audio data on PCs, they were
simply resorting to PIT reprogramming.

I tested it and it works as expected, although results are quite
jittery due to the relatively poor precision of interrupts firing. DMA
transfers are vastly superior in this regard.

Mateusz

Back to comp.os.msdos.programmer | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

is there a high-frequency timer available on the PC? (besides the PIT) Mateusz Viste <mateusz@xyz.invalid> - 2022-08-17 12:01 +0200
  Re: is there a high-frequency timer available on the PC? (besides the PIT) Johann Klammer <klammerj@NOSPAM.a1.net> - 2022-08-17 19:02 +0200
  Re: is there a high-frequency timer available on the PC? (besides the PIT) rridge@csclub.uwaterloo.ca (Ross Ridge) - 2022-08-19 15:25 +0000
    Re: is there a high-frequency timer available on the PC? (besides the PIT) rridge@csclub.uwaterloo.ca (Ross Ridge) - 2022-08-19 19:44 +0000
      Re: is there a high-frequency timer available on the PC? (besides the PIT) Mateusz Viste <mateusz@xyz.invalid> - 2022-08-19 22:16 +0200
        Re: is there a high-frequency timer available on the PC? (besides the PIT) "Alexei A. Frounze" <alexfrunews@gmail.com> - 2022-08-19 21:20 -0700

csiph-web