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From: ers@cbnewse.cb.att.com (eric.r.sterbenz)
Subject: Re: HELP!
Organization: AT&T
Date: Fri, 11 Mar 1994 20:02:05 GMT
Message-ID: <CMInnL.DG8@cbnewse.cb.att.com>
Lines: 43
Xref: cdrom.com alt.cd-rom:1583 alt.sys.pc-clone.gateway2000:1441 comp.sys.ibm.pc.hardware.cd-rom:1721 comp.sys.ibm.pc.soundcard:8425


Folks,

I posted an article earlier this week about a problem I was having with
my Mitsumi FX001D and my Orchid GW32 card controlling it.  In a
nutshell the problem was that it had worked fine for several weeks and
suddenly started not detecting the CD-ROM drive on power up.  

Well thanks to some helpful people at Micro Center, they jogged my
memory and we found the problem.  The basic problem was that whenever
you change the GW32 configuration from GMIDI to MT32 or back, the
configuration program re-edits your CONFIG.SYS file and puts the
SWCD.SYS driver at the end of the file.  In this case it was placing it
after the Mitsumi driver's definitiion)!  I remember noticing this
before, but it was before I had a CD-ROM drive and thus didn't matter.
Anyway, now I know (I won't forget again), and am passing this on to
help keep anyone else from falling into this trap.

Item 2:

Thanks to a coworker I have also been able to benchmark the Mitsumi
FX001D using the Mitsumi provided controller with and without DMA
access.  (There had been some postings in various newsgroups about the
DMA channel mismatch between the Orchid cards and the Mitsumi driver).
I am happy to report that Orchid was correct about DMA access (this
should not be a suprise based on some recent postings about DMA).
Anyway the performance on a 486 class machine using the DMA driver in
interrupt mode is significantly better than using DMA mode.  My
coworker has a GW2K 4DX2-66V (he has a lot of stuff running).  With DMA
mode the using MPC Wizard 2.0 the best he could get at 100% cpu was
about 305 KB/s.  Using interrupt mode it jumped to about 365 KB/s.  This
is much more consistant with my results (GW2K 4DX-33V using the GW32 as
a controller) of a consistant average around 380 KB/s.  By the way I
believe GW2K distributes their Mitsumi drives configured for DMA with
the minimal amount of buffers.

I hope that anyone trying to get the optimal performance out their
CD-ROM finds this information usefule.

Thanks,

Eric
ers@cbnmva.att.com