From: jnh@hal.eng.ufl.edu (Jordan Hazen) Subject: Re: Problems with PAS-16 Date: 29 Aug 1993 04:12:20 GMT
This happens on my machine when the bus gets too loaded down (I have an ISA video card,
and this often happens even when CPU load figures are rather low). Playing music on the
PAS-16 often uses more bus bandwidth than doing so on the SB because the PAS16 supports
stereo sound up to 44.1kHZ, with 16-bit samples, while the Soundblaster supports only
mono 8-bit sound at (I think) 20kHZ or so. The 16-bit bus of the PAS16 helps some, but
can't compensate completely for the increased data xfer rate.
If your BIOS/chipset supports it, try increasing the AT bus clock rate as much as your
system can tolerate; I'm running mine at 13.5MHz or so with no problems, but I did have
to remove an older XT multi-IO card that couldn't tolerate the faster speed (it would
lock up the computer on boot). Many BIOSes have an entry in the setup program where
you can specify the factor by which to divide the CPU clock to get the bus clock; set
this number as low as possible (i.e. 33MHz / 2.5 instead of 33MHz / 4). For an AMI
486 BIOS, this option should be in the "advanced chipset configuration" page. You might
also be able to set this through a jumper on your motherboard.
If you're playing MOD files, also use 8-bit sampling instead of 16-bit (it makes
negligible difference, since the original Amiga chipset had only 8-bit sound). Switching
to monaural mode or decreasing the sample rate will also help (at the cost of poorer
sound quality).
This usually only happens in X-windows because of the increased video-related bus traffic
when in graphics mode... switching to a VLB video card should fix this problem, though
I've never tried it. (I'm using a PAS16 on a 486-33 w/ISA video).