Sorry for the long delay in summarizing, I wanted to make sure there
were no "straggler" responses, and then I was swamped by a series of
My original request was:
> We are looking to add additional serial ports to our IPCs.
> We have been using the Sun "Serial Parallel Controller", but have had
> problems with this product. In addition, it ties up an Sbus slot.
> We are looking for alternatives to this product, particularly (but not
> exclusively) those that do not use the Sbus. We know about at least
> one SCSI-bus based serial extender, from Central Data.
> If you have had experiences, good or bad, with this or any other serial
> expander product, I would be most interested in hearing about them.
Responses came in four flavors:
Sbus-based expanders (and Sbus expander)
Ethernet terminal servers
Because our requirements are perhaps somewhat unique, the terminal
server is not a viable option, and the Sbus expander is probably not
cost effective. Consequently, I did not dig for more info than was
emailed to me. I've included what info I have in the summary.
A thorough survey would include individual and aggregate throughput
specs. However, because bandwidth is not crucial to our application, I
have not dug for those data points.
A thorough survey would also include whether or not the serial ports
support: full modem control, synchronous RS-232-C, RS-422. Maybe one
of the mags (Sun World/Expert/Observer/...) will fill in the blanks.
We have not determined what route we will take. Next step will be to
evaluate the SCSI-bus expanders and the serial multiplexer. If that
becomes a priority (i.e., when it becomes a crisis ;-) and we actually
get around to doing it, I will post a further summary.
Thanks to everybody who responded.
If anybody wants a copy of ALL the email I received (56K bytes), I will
be happy to forward it.
Format of summary:
Vendor: name of vendor
Address: address of vendor
Phone: phone number of vendor
Fax: fax number of vendor
Contact: contact persons at vendor
Product: name, type, or general description
Ports: s/p, s/p, ...
Ref from: non-vendor respondents that mentioned product
Notes: my comments
re: Ports info: s/p => number of serial/parallel ports
s/p ... s/p => indicates endpoints of range of products
Vendor: Sun Micro
Product: SPC (Serial Parallel Communications card)
Notes: kit was uprev'ed without notification,
kernel with old driver does not work with new unit :-(
Vendor: Aurora Technologies, Inc.
Address: 176 Second Ave.
Waltham MA 02154
Contact: Jeff Martin (firstname.lastname@example.org)
Steve Valencia (email@example.com)
Product: family of serial expanders, and Sbus expander
Ports: 16/0, 8/0, 4/0, 2/1, 0/1, 0/2
Ref from: David Gunn (firstname.lastname@example.org)
Notes: suggest using Sbus expander
Vendor: GNP Computers
Ports: 8/1 ... 32/4
Ref from: John Uhley (email@example.com)
Kevin Sheehan (uunet!fourx.Aus.Sun.COM!kalli!kevin)
Notes: Uhley wrote driver for GNP,
Kevin is happy with his unit
Product: family of serial expanders, Sbus expander
Ports: 3/? ... 16/?
Ref from: Brian Woodson (Brian_Woodson@3com.com)
Vendor: Central Data
Address: 1602 Newton Drive
Champaign IL 61821
Ports: 2/1, 8/1, 16, 0/3, ... 392/49
Ref from: stephen dowdy (firstname.lastname@example.org)
Jeff Crilly (email@example.com)
Russ Poffenberger (firstname.lastname@example.org)
Don Mac Leod (email@example.com)
Notes: well liked, easy to install, "it works"
old driver sometimes failed to see unit at boot time
Vendor: Uninet Peripherals, Inc.
Address: 17981 Skypark Circle, Suite O
Irvine, CA 92714
Phone: (714) 263-4222
Fax: (714) 263-4299
Contact: Neil Gorsuch (uunet!uninet!neil)
Product: SLAT -1, -2, -3, -4 (families of serial expanders)
Ports: many combinations, incl: 0/1, 0/2, 4/1, 8/1, 12/1, 16/0
Notes: serial ports are RJ45 (DB25 adapter available)
parallel ports are DB25
other parallel interfaces: Data Products, DRV11-J, Versatec
No special device driver needed, unit emulates SCSI disk!!!
(daemon process services I/O requests via ptys)
Working on a high-end unit (~500000 cps aggregate)
Vendor: Vector Technologies
Address: 3289 E. Hemisphere Loop
Tuscon, Arizona 85706-5028
Phone: (602) 741-0120
Fax: (602) 889-5790
Ref from: Marcel Bernards (Bernards@ECN.NL)
Notes: ref. from co-worker (no direct experience)
aggregate bandwidth must be limited by max
bandwidth of Sun serial port
Ethernet terminal servers
Ref from: Brent A. Wiese (firstname.lastname@example.org)
Jim McManus (uunet!Think.COM!jjm)
Notes: Brent is happy with his unit,
Jim is evaluating one
Product: Annex 3
Ports: 8/? ... 64/?
Ref from: Stuart McRobert (uunet!doc.imperial.ac.uk!sm)
Notes: "integrates into unix well (tip, cu, printing software work fine)"
-- .. Steve Harris - Eaton Corp. - Beverly, MA - uunet!etnibsd!vsh
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