Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!sdd.hp.com!hplabs!hp-pcd!hpfcso!hpfcdj!kinsell
From: kinsell@hpfcdj.HP.COM (Dave Kinsell)
Newsgroups: comp.sys.hp
Subject: Re: Fast Parallel I/O and DSP for HP9000
Message-ID: <17330016@hpfcdj.HP.COM>
Date: 8 Jun 90 01:59:32 GMT
References: <848@kudpc.kyoto-u.ac.jp>
Organization: Hewlett Packard -- Fort Collins, CO
Lines: 26


>I am wondering if I can use fast HP-IB or SCSI bus for the data tranfer.
>Is it difficult to use such bus like SCSI for data transfer?
>How fast are these buses with HP9000/300 series?

>Mamoru Yamamoto

The high-speed HP-IB is rated at 1.0 meg/sec, but will typically burst
data at about 1.2 meg/sec.  The SCSI on the 345, 375, and 98265A products
will negotiate for a 4 meg/sec burst rate, and are able to sustain that
for 64K bytes at a time during reads.  On writes, a rate of 3.6 meg/sec
is achievable.  The 98658A board will negotiate for a 2.67 meg burst rate,
and average about 2.

HP-IB chips that run at the meg/sec rate are not readily available
commercially.  You could do a TTL implementation, but SCSI would be a
much better choice.  Protocol chips are available that have integrated
bus drivers, and provide a simple handshake interface to your data path.
An initiator driver for the Fujitsu family of chips is available in
/usr/lib/drivers with the PE product.  This could serve as the base for
a target implementation.

Best regards
Dave Kinsell

In no way officially representing Bill and Dave.