From: terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.)
Newsgroups: alt.cd-rom,comp.periphs.scsi
Subject: Re: CD-Rom & Adaptec 1542b
Date: 20 Aug 92 04:37:26 GMT
Organization: St. Peter's College, US

In article <pm!ngp=@dixie.com>, jgd@dixie.com (John De Armond) writes:
> I need to buy a high speed CD-Rom player known to be compatable
> with the adaptec 1542b host adaptor when the CD-Rom drive is at
> a physical address >>1.  

  By high-speed, do you mean one of the double-RPM-rate drives that are
just now becoming popular, or do you mean access time?

  I have a Sony SCSI CD (541, I think) at address 5 on a 1542B. Works fine.
  I have used a NEC something (CDR-83?) at address 2 in the past. Likewise.
  Neither of those are particularly slow, but they're not double-speed.

> Please reply by mail, as I need advice faster than news normally
> flows.  

  Sent by news and by mail.

> Muse of the day.  After spending the last two days and nights trying
> to get the 1542b to talk to a Syquest SQ555 removable hard drive
> and a Matshita CD-ROM (panasonic clone), I just gotta ask.  How the
> hell does Adaptec manage to f*ck up so badly?  Both devices work 
> with Future domain, Allways, DTK Segate ST01 and even the Trantec parallel 
> port host adaptor.  Why is it every time I get near an Adaptec host
> adaptor, I can just plan on trashing a day or so?  Last time it was
> an Exabyte, time before that it was a newbury hard drive, before
> that an Archive cartridge tape drive.  In each case, the official
> adaptec advice has been "get new firmware for the offending device."

  In many cases that _is_ the problem. A lot of the drives kicking around
(in both the wholesale and retail channels) are "Mac version" or "Sun
version" drives with variant firmware. The _only_ problem I've seen with
the 1542B is that the ASPI driver doesn't delay long enough after a hard
reset to let some devices finish self-test. This is only a problem on DOS.

> While I'm at it, anyone have a suggestion for a host adaptor that
> will do the following:
> 
> *	Run with windows without double buffering

  The 1542B does this if you have the ASPI manager (ASW-1410?) loaded. Works
just great. I've been running with it for many months now.

> *	Do what microsoft calls "32 bit transfers."

  I'd suggest that you _don't_ want this. First, it isn't 32 bit transfer
mode, and second, it requires a controller which is register-compatible
with the original AT HD controller. I don't know of _any_ SCSI controllers
which are register-compatible. My experience with register-compatible ESDI
controllers indicates that most vendors get it wrong (at least CompuAdd and
Everex do). SCSI implementations run from "dumb parallel port" (like the
earliest Future Domain cards) through advanced cards like the 1542B.

> *	support the Syquest drive.

  I wouldn't be caught near a Syquest (dates from my original experience w/
their 5Mb version which had "removable media" which was a matched set with
the drive firmware - cartridges weren't swappable between drives). However,
what sort of errors do you get?

> *	support the Exabyte

  I'm a 1/4" person myself. I don't know why an Exabyte wouldn't work, other
than the previously-mentioned vendor-specific firmware variants in the drive.
I know that every time there is a new VMS release the drive firmware needs to
be changed 8-). However, Sytos Plus supports the Exabyte drives on the 1542B
- why don't you ask them what formware versions they support?

> *	Support a CD-ROM

  See above. Both Sony and NEC work fine.

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, Jersey City, NJ USA
	terry@spcvxa.spc.edu	+1 201 915 9381