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Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point)
From: |
Sebastian Kaliszewski |
Subject: |
Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point) |
Date: |
Wed, 25 Jan 2006 01:38:39 +0100 |
User-agent: |
KMail/1.4.3 |
On Tuesday 24 January 2006 22:45, Fabrice Bellard wrote:
> If you want to model the real PC speaker, the best to do is to generate
> a square signal and to pass it thru a low pass filter with a cut off
> frequency of a few kHz. Then you could even be able to play samples thru
> the simulated PC speaker using the tricks used in old MSDOS programs,
> provided QEMU implements a precise cycle counter (it will come someday
> !).
Change that few to 15 [kHz] and that would be what some PC-speaker hooking
SB-clones did. But there were PCs with piezoelectric speakers, and those
could genereate sounds well above 20kHz. But yes, typically 12-15kHz cutoff
with 1st or 2nd order filter would do the trick.
And if someone wants full reality one would also need some not-too-strong
(1st order, 6dB/oct) hi-pass filter around 80-120Hz -- as those tiny
PC-speakers are unable to emit bass.
rgds
--
Sebastian Kaliszewski
- [Qemu-devel] [PATCH] PC speaker emulation (fixed), (continued)
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed), Sebastian Kaliszewski, 2006/01/20
- [Qemu-devel] [PATCH] PC speaker emulation (fixed point), Joachim Henke, 2006/01/23
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point), Sebastian Kaliszewski, 2006/01/24
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point), Joachim Henke, 2006/01/24
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point), Sebastian Kaliszewski, 2006/01/24
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point), Fabrice Bellard, 2006/01/24
- Re: [Qemu-devel] [PATCH] PC speaker emulation (fixed point),
Sebastian Kaliszewski <=
- [Qemu-devel] [PATCH] PC speaker emulation (square wave), Joachim Henke, 2006/01/25
- Re: [Qemu-devel] [PATCH] PC speaker emulation (square wave), Jamie Lokier, 2006/01/25
- Re: [Qemu-devel] [PATCH] PC speaker emulation (square wave), Sebastian Kaliszewski, 2006/01/26
- Re: [Qemu-devel] [PATCH] PC speaker emulation (square wave), Joachim Henke, 2006/01/29