[comp.sys.nsc.32k] Looking for SCSI board

AARDVARK@ENI.Prime.COM (11/28/89)

I have an old 32016 development system which has the *old* 20 Mb disks
with the no-longer-supported-by-anyone (and for good reason :-) X3.101
interface (pre-scsi).  Does anyone know whether there exists an I/O
board that supports SCSI (and appropriate drivers)?

Don Koch
Internet mail: aardvark@primerd.prime.com
Disclaimer:  The above reflects only my views and not those of my employer.

john@starfire.UUCP (John Lind) (11/30/89)

In article <51900003@ENI.Prime.COM>, AARDVARK@ENI.Prime.COM writes:
> I have an old 32016 development system which has the *old* 20 Mb disks
> with the no-longer-supported-by-anyone (and for good reason :-) X3.101
> interface (pre-scsi).  Does anyone know whether there exists an I/O
> board that supports SCSI (and appropriate drivers)?

Well, I am assuming that your development system is a MultiBus (I) system,
since you didn't actually say.

Several people make MBI SCSI HBAs, but the only one I have experience with
is the Rimfire 1500 from Ciprico.  This may be more board (and more money)
than you want.  The PC board is pretty full, because this is a full-featured
controller.  It uses a custom Short Burst Fifo chip, custom Bus Controller
chip (for the host bus), and a fast third-party SCSI state-machine bus
interface chip, and an i80186 for the on-board processor.  This baby clips
right along.  It has a single-command mode, but the usual mode of operation
is through a command list in the host memory.  The driver interprets
IO requests into commands in the command list, bumps the pointers, and tells
the board to check the queues.  That's all you have to do until the command
is completed.  The controller uses a "pass-through" scheme for a number of
reasons -- the command consists of a header of information that is just
for the controller to use (memory address and such useful things), followed
by the SCSI CDB (Command Data Block) pretty much as it will be sent out on
the SCSI bus.

The board is available with or without a floppy disk interface.  Floppies
are handled through the command list as if they were SCSI devices --
you use a psuedo-SCSI target ID of FE (SCSI target IDs are 0-7, so this is
safely out of range).

The board is available in single-ended or differential configuration (very
few differential peripherals exist, however), and a SCSI-II version is
under development to do SCSI FAST and SCSI WIDE.  The orignal controller
supports mixed synchronous and asynchronous devices at very high transfer
rates, disconnect/reselect, and pretty much anything else you would expect
from a high-performance SCSI HBA.

I own a Ciprico Tapemaster 1000 and a Rimfire 1400, and can speak for them
as well-built products.  They are serving starfire quite well.  I do not
myself own a Rimfire 1500, but am currently under contract with Ciprico
to do some custom firmware changes for one of their customers.

So, a dis-disclaimer.  I do work under contract for Ciprico, and have been
an employee of theirs.  I have many friends there, but none of them nor I
will directly benefit from the sale of a controller.  In fact, you won't
be able to buy one from them directly, since they don't do retail sales.
However, if you give them a call at 612-559-2034, they will be able to
put you in contact with the distributor/sales rep for your area.

Please let me know if you follow up on this -- I would love to get your
opinion of the controller.
-- 
	       John Lind, Starfire Consulting Services
E-mail: john@starfire.MN.ORG     USnail:   PO Box 13001, Mpls MN  55414

john@starfire.UUCP (John Lind) (11/30/89)

Argh!  Concerning the Ciprico Rimfire 1500, I forgot a very important
feature -- it supports Scatter-write/Gather-read for all you folks
with a paged memory scheme.  You don't need to use a bounce buffer for
this guy -- just give him the list of starting addresses and lengths
for the physical memory fragments of the buffer, and it will go to it.
For Unix users, this is only important for the raw (character) device
interface, but if you are using your SCSI bus for tape, this is very
important indeed -- things like tar and dd run much better if you
don't have to bounce the data through a contiguous memory buffer, and
who wants to wasted 32-126K of memory, anyway?
-- 
	       John Lind, Starfire Consulting Services
E-mail: john@starfire.MN.ORG     USnail:   PO Box 13001, Mpls MN  55414