Hi everyone, I've built a 486 pc using a Pro Audio Spectrum 16 but when I use the full speed of the CPU at 66Mhz the audio is very scratchy but using the turbo button to slow the pc down it sounds fine and clear, if I change the AT bus clock from CLK/4 to CLK/5 I get clear sound at 66Mhz is this safe to run the ISA clock at CLK/5 for the PAS16 and if it is is it also safe for a MPU-IPC-T card.
66 MHz 486 CPU uses 33 MHz bus. So:
CLK/4 = 33 MHz / 4 = 8.25 MHz
CLK/5= 33 MHz / 5 = 6.6 MHz.
Both are very safe. AT Bus clock was standardised in ISA standard at about 8.33 MHz.
It is weird that it makes any impact on sound quality though.
IIRC someone here said the PAS16 needs a 2/3/486 as using a faster Pentium is too fast for it and I found for this pc build a game could have the audio option for the PAS16 and sound scratchy but the "Pro Audio Spectrum" option has clear sound so i was disabling the motherboard cache to get clear sound but my adventure games characters were walking very slow. Ide rather use CLK/5 and the cache on or use Pro Audio Spectrum setting as I can't hear much difference between PAS and PAS16.
Is it ok to run a MPU-IPC-T card at CLK/5 6.6MHz for an MT32 and SC55
HAPPY NEW YEAR everyone
Hi! I was using my PAS16 in a 286-12 originally, but kept it up to ca. a Pentium 75 to 133.
I'm not 100% sure, but I believe that 286 ran both CPU and BUS at same speed (12MHz).
The Pentium ran Windows 98SE (and Windows 3.10) and my PAS16 worked out-of-box.
If you encounter trouble, please make sure the PC's PSU has got -5V.
Additionally, try booting DOS without EMM386. That once worked for me..
PS: Happy New Year, too! 😁
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