SCSI connectivity

From: <(>
Date: Sat Mar 10 16:45:52 2001

> Date: Sat, 10 Mar 2001 22:24:25 -0500
> From: Chad Fernandez <>
> To:
> Subject: Re: SCSI connectivity
> Reply-to:

> That's true, but you aren't using the full capacity of the slot. I
> suppose if you already have an ISA card, and don't really want to spend
> anymore it's fine. I have a setup like that. I have a VLB slot with a
> ISA 1542B installed. I haven't actually gotten the computer up yet....
> still have some IRQ/DMA conflicts, I think.

Straighten it out then! :-)

> SCSI is backwards compatible as long as you keep Single Ended and
> Differential separate. I would think any high end 486 class machine
> would benefit from wide scsi. Remember SCSI doesn't rely on the CPU
> like IDE does.

Uh uh... usually not. Most of ISA scsi cards doesn't have the
capablities to off load the cpu task to the cards. Plain scsi 1 and
scsi 2 is very slow than compareable IDE pio 2 or up w/ VLB cards or
pentium boards are already busmaster by hardware. Go wide.

Even PCI scsi cards is usually plain. Would have to look hard to
find a true high performance scsi card that has all the smarts and
busmaster by default. Very rare isa have busmaster, I don't know
for sure on VLB. EISA cards usually have both cpu or on board
processor. On winblows drivers is a big problem on older scsi cards
especially on brands that went under or bought out.

anyway to use them for non-performance issues. Great for you.

> I actually have a pair of 8-bit SCSI cards, a Seagate, and an NCR. I
> have used the Seagate, unfortunately it didn't see more than 2xx of the
> 300megs of my HD, after I repartitioned the HD on that controller. I
> wish I had any drivers, or utilities that would have been included with
> it originally. It would be neat to hook a cd-rom to it. I haven't
> experimented with the NCR, other than seeing if Windows 9x would see
> it... it didn't.

This is one you touched on this issues I raised above. NCR support
is nearly nothing under winblows. DOS drivers is very hard to locate
unless someone has the drivers on hand to copy for u. Seagate scsi
card is fixed, very limited support to segate drives only, dumb
hardware robbing the cpu power for data tranfers. And needs driver
to support any other drives and cdroms. Very slow anyway. I had
few, finding out this then threw them out.

> Chad Fernandez
> Michigan, USA


Received on Sat Mar 10 2001 - 16:45:52 GMT

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