furuta@tkov51.enet.dec.com (My name is Akihiro Furuta) (10/17/90)
I want to hook up hard disks to Sparc Station. Sparc has SCSI II type connector and hard disks on market usually have SCSI I type 50-pin Anphenor connector. Where can I buy such cables in US? Akihiro Furuta Digital Equipment Corp Japan
chris@com50.c2s.mn.org (Chris Johnson) (10/19/90)
In article <1990Oct17.022235.22598@tkou02.enet.dec.com> furuta@tkov51.enet.dec.com (My name is Akihiro Furuta) writes: >I want to hook up hard disks to Sparc Station. Sparc has SCSI II type >connector and hard disks on market usually have SCSI I type 50-pin Anphenor >connector. Where can I buy such cables in US? > >Akihiro Furuta >Digital Equipment Corp Japan Sun calls the SCSI connectors on the rear of the SPARCstations a micro-miniature SCSI connector. These connectors have 50 pins. I don't believe that the SCSI 2 specifications include that connector as one of the standard connectors, but I could be wrong. Does someone have a copy of the spec. and would be willing to check? I think it's probably a misnomer to call that connector a SCSI 2 connector. Sun implements a few of the SCSI 2 command features in its latest machines, but does not, for example, support fast or wide SCSI 2. The connector on most SCSI hard disks is a dual-row 50 pin flat cable connector, and it is indeed one of several connectors specified in the SCSI 1 specification as being a standard connector. A 50 pin Centronics-style connector is another of the standard connectors. I've heard that the Sun "micro-miniature SCSI" connectors are made by Honda. I've also been told that 3M now makes an equivalent connector. AMP (Amphenol) also makes them, since they are on the cables I have laying here. I believe we bought the cables we have here from a distributor called DataLink. I would image many of the larger cable and electronics parts distributors like Anthem, Americable, and Pioneer would carry the connectors, but I don't know about any specific company. And of course, Sun sells a micro-miniature to 50 pin D (conveniently non-standard for SCSI) cable, and it's easy to get 50 pin D to 50 pin dual row parts for conversion cables. I can just imagine what all this connector conversion stuff does to cable impedances being correct. I'd certainly like to know if there is a company that sells a cable that has the micro-miniature connector on one end and the dual row on the other. -- ...Chris Johnson chris@c2s.mn.org ..uunet!bungia!com50!chris Com Squared Systems, Inc. St. Paul, MN USA +1 612 452 9522
jgotobed@lpl.arizona.edu (Joe Gotobed x4549) (10/21/90)
In article <1990Oct17.022235.22598@tkou02.enet.dec.com> furuta@tkov51.enet.dec.com (My name is Akihiro Furuta) writes: >I want to hook up hard disks to Sparc Station. Sparc has SCSI II type >connector and hard disks on market usually have SCSI I type 50-pin Anphenor >connector. Where can I buy such cables in US? > >Akihiro Furuta >Digital Equipment Corp Japan I bought one from Sun to hook an 8mm Exabyte to a SparcStation. It was a hundred bucks or more. I've got a Toshiba CD palyer with what looks like a Centronix style printer connector for it's SCSI port that I need to connect to the Sun SCSI-I (? 3row/50pin) I'd like to get a 15 foot cable.... where can I get such a beast? It's the same SCSI connector as my VAX 3520 maybe DEC? :-) Thanks Joe
esmith@goofy.apple.com (Eric Smith) (10/21/90)
In article <1990Oct19.164911.24264@com50.c2s.mn.org> chris@com50.c2s.mn.org (Chris Johnson) writes: > And of course, Sun sells a micro-miniature to 50 pin D (conveniently > non-standard for SCSI) cable, and it's easy to get 50 pin D to 50 pin > dual row parts for conversion cables. Do you mean 50 pin D or 25 pin D? 25 pin D, while it is not part of the standard, has gained considerable popularity since the introduction of the Macintosh Plus in 1986. In addition to Macintoshes, I have seen it used on Commodore Amigas, and IBM-compatible systems. Not that I think it's a good connector for SCSI, but it has become a defacto standard of sorts. -- Eric L. Smith Opinions expressed herein do not necessarily reflect those esmith@apple.com of my employer, friends, family, computer, or even me! :-)
wilker@gauss.math.purdue.edu (Clarence Wilkerson) (10/22/90)
One note of caution in making your own cables. The standard numbering on a DB-50 plug or socket do not match up with the standard 50 line flat cable clamped to such a socket. To illustrate, the plug may come marked as ( or mirror image of this ) 1 2 3 4 .... 17 ( top row) 18 19 20 ...... (middle row) 34 35 36....... (bottom row) However, if you clamp this onto to a flat cable the correspondence is more like DB50 cable 1 1 18 2 34 3 2 4 etc Fortunately, the female socket on the back of a sun 3/50 is clamped onto a flat 50 pin cable, so the above change cancels out the change of pin assignments on the DB50. That is, an even number of such mappings cancel out in the sense that a flat 50 pin cable at the end will have the standard "scsi" pin assignemnts. I'm repeating this because the sun hardware manual is very unclear on this. In summary, except for pin 26 ??? termination power questions, and RFI problems, you should be able to make a working cable by taking a standard clampon insulation displacemnt type DB-50 male plug, on a 50-wire flat cable on one end, and a 50-pin centronics connection on the other, if the centronics connector pin connections are the scsi standard. However, if you are handwiring the cable, do NOT connect pin x of the DB-50 to pin X of the centronics connector.
chuckl@chips.com (Chuck Linsley) (10/23/90)
In article <1990Oct19.164911.24264@com50.c2s.mn.org> chris@com50.c2s.mn.org (Chris Johnson) writes: >Sun calls the SCSI connectors on the rear of the SPARCstations a >micro-miniature SCSI connector. These connectors have 50 pins. > >I don't believe that the SCSI 2 specifications include that connector >as one of the standard connectors, but I could be wrong. Does someone >have a copy of the spec. and would be willing to check? I'm not sure what is on the SPARCstation, but SCSI 2 specifies a high-density connector with 2 rows of pins on 0.05 in (1.27 mm) pitch, with 0.1 in (2.54 mm) spacing between the rows. >I think it's probably a misnomer to call that connector a SCSI 2 >connector. Sun implements a few of the SCSI 2 command features in its >latest machines, but does not, for example, support fast or wide SCSI 2. It doesn't have to support fast or wide to be SCSI 2; they're options. As long as they implement the features that are mandatory, it's SCSI 2. >I can just imagine what all this connector conversion stuff does to >cable impedances being correct. Don't worry; it probably wasn't right anyway. ;-) Chuck Linsley Chips and Technologies, Inc. Mass Storage Operation #include <std_disclaimer.h> chuckl@chips.com