#GVP A4008 SCSI PROBLEMS
6 messages in this thread
Thomas,
Unfortunately, getting the right DMA and MAX TRANSFER settings depends on how
the other product works. Centaur would be your best resource for getting
specific settings for you drives RDB.
GVP TECH
GVP, I have got around some of the problems thanks to a great DMA reference
sheet that I obtained. What I have done is set the DMA to 0x00fffffe That has
seemed to clear up the opalscreen problem, but it has also seemed to slow down
the drive a bit, is there a better setting I should try? I don't have much
knowledge of how to set DMA and what they should be, but I would apreciate and
welcome your sugestions on different settings anlong the same track as the one
above. Thanks
Thomas
0x00fffffe, if I am correct, would place all DMA activity in the 24-bit DMA
memory range (such as on-board A4008 memory), and restricts it from 32-bit
memory (on accelerators and A3000/4000 motherboards). I don't know if this
information helps you at all, or if anyone has more accurate information, but
there's my $0.02.
Gary Nush
Gary, Well that must be why it's slower, the fact that I don't have any 16bit
simms o on the a4008 doesn't help much. Is it o.k to mix these two types of
memory? I have 18megs of 32bit ram on the 4000/030 mother board. Is it safe to
add 16bit memory to the a4008?
Thomas
It's certainly safe, but you really only need the minimum 2MB. That's enough
to support the DMA transfers. If the system runs out of 32-bit memory, it will
automatically begin using the 16-bit memory, but keep in mind that it will slow
the system down if it indeed begins using it.
Then again, with 18MB of motherboard memory, you might not run into that
situation…
Gary Nush
Gary, Hmmm Well I was just wondering because of speed, now that I have set the
dma to 0x00fffffe to cure the OpalVision problem it has Slowed down the
transfer rate quite a bit. Also I still have the hardware data overrun error
when using the modem, I tried GVP Patch but it did not work for my set up.
Anyway to get the best of both worlds? Speed & Performance?
Thomas