From: kan@yoyodyne.rtp.dg.com (Victor Kan)
Subject: Re: DMA-problem with PAS-16
Date: 12 Jan 93 18:32:04 GMT
Distribution: comp
To: luru@stekt7.oulu.fi (Ari Husa)
Reply-To: kan@dg-rtp.dg.com
Organization: Program Development Environments, Data General Corp., RTP, NC

>>>>> On Tue, 12 Jan 1993 14:01:32 GMT, luru@stekt7.oulu.fi (Ari Husa) said:

Ari> In article <4954@svin09.info.win.tue.nl>
Ari> wstapda@wsinfo01.win.tue.nl (Patrick D. Anderson) writes:

> Summary: can't use high dma-channels

Ari> Neither can I.

I just tried it this weekend.  It works to some extent.

> Under Windows I am allowes to choose a high DMA-channel, but a
> restart results in a memory-parity error on board, before I've even
> tried to get some sounds.

Ari> Mine does the same thing. Anyone gotten the damn thing work with
Ari> higher DMA channels?

My system is a TriStar 486/33 ISA with the infamous OPTi chipset (8Mb
RAM, 128K write back cache), Diamond Stealth VRAM, generic I/O card,
Music Quest PC MIDI card and PAS-16.  The PAS-16 is the only card that
I know uses DMA.  I guess the Stealth might, but I didn't check the
manual thoroughly to find out.  Is there another way to check what DMA
channels are being used by whom?

DMA channel 5 doesn't work at all, causing some memory access
violation in Windows when the opening "TADA" sound plays, causing a
*cold* boot.

DMA channel 7 works, but periodically causes problems that look like a
conflict with the video.  BUT, if I turn off the external RAM cache,
it seems to be more reliable.  Of course, performance slows down
significantly without the external cache.

DMA channel 6 works, and doesn't seem to have problems like DMA
channel 7 even with the external cache turned on.  But it's the DMA
channel that the PAS-16's manual warns against using for some reason.
I'm using it for now, but I've sent a message to TriStar's tech
support BBS asking about this (and other DMA problems known to occur
with OPTi chipsets, e.g. the Adaptec 1542B SCSI host adaptor).
Hopefully, they'll admit that it's a problem with the motherboard and
send me a new one with the updated OPTi chipset, or better yet, their
new Micronics VL-bus motherboard!

They haven't gotten back to me yet and I'm keeping my fingers crossed.

BTW, what does the DMAFIX program that comes with the PAS-16 do?

Ari> I also do seriously hate the fact that "most DOS applications"
Ari> (as the manual puts it) work neither with "high" IRQ or DMA
Ari> settings (not to mention the fact you need TWO of them for
Ari> PAS16). My machine is rather crowded, and there simply are not
Ari> enough low IRQ's and DMA channels available - I have other
Ari> braindead 8-bit hardware as well..

It's not MediaVision's fault that many DOS apps don't work, is it?
Aren't the high IRQs and DMAs available only on ISA bus machines so
older applications that only support the old XT bus and badly written
apps that make unreliable assumptions about sound cards the
limitation?

The manual also says that you can have the PAS part of the card share
DMA channel 1 with the Soundblaster part since most software doesn't
use both simultaneously.  It would be nice if they could share an IRQ
as well, using some I/O port to toggle between Soundblaster emulation
vs. native PAS mode.  But I guess the way it works now, it's like
having two sound cards installed at the same time.

--
| Victor Kan               | Internet: kan@dg-rtp.dg.com            |  ***
| Data General Corporation | Usenet:   ...!mcnc!rti!dg-rtp!kan      | ****
| 62 T.W. Alexander Drive  | Them: "It was delivered to Georgia."   | **** %%%%
| RTP, NC  27709           | Me:   "But the label said Arizona!"    |  *** %%%
Newsgroups: comp.sys.ibm.pc.soundcard