10 Mar
2001
10 Mar
'01
5:51 p.m.
Installing the 1542B in a VESA slot won't give you performance beyond the ISA,
since it only uses the ISA. If you can find a 284x, you'll be pleased with its
performance, though.
I've used a 2842 in a machine with both VLB and PCI cards and that one ( AMD
5x86 at 160 MHz) was entirely indistinguishable in its performance from a 2940
with the same number of similar drives.
The 1542B is a pain because of its poor documentation but can be made to work
OK. If you can get one, the 154xA version is probably as good as any and
performs up to ISA spec's. What's more, its jumpering, though plentiful and
confusing, is well documented.
Dick
----- Original Message -----
From: "Chad Fernandez" <fernande(a)internet1.net>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, March 10, 2001 8:24 PM
Subject: Re: SCSI connectivity
ajp166 wrote:
Yes, but most ISA-8 or and ISA-16 cards do fit
EISA and VESA
bus machines as they generally provide ISA. I know that as I have a
boat load of antiques at work still running.
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.
Most wide SCSI drives work just fine with narrow.
It's not as if the
machine is likely to be fast enough to really use wide SCSI
performance.
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.
I generally use a ISA card from ADAPTEC as I have
a 1542 and a 2906
(PCI) handy. That works in everything but the XT class boxen and MCA.
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.
Chad Fernandez
Michigan, USA