bernards@ecn.nl (Marcel Bernards) (10/23/90)
Hi,
Just a silly question perhaps, but I'm asking anyway.
As a Sun System Manager I'm doing a lot of installation/upgrade
jobs. For these purposes I purchased The SunCD and a desktop QIC-150
1/4" cartridge tape unit.
As the SCSI bus wants all devices in a single chain with the
terminators at the end, it's quite annoying shutting down my SLC
every time I have to uncable my desktop stuff for an installation job.
The present configuration is like this
SLC--TAPE--CD--WRENVI-TERMINATOR
What I'm looking for is a small patch box whith buffers in it,
which allows to connect SCSI devices in a star shape, and allows
to disconnect the devices safely without shutting my SLC down.
Like this:
+------------------WREN_VI----TERMINATOR
| +----------------SUN-CDROM--TERMINATOR
| | +--------------SUN-QIC150-TERMINATOR
| | | +------------EXTRA------TERMINATOR
+-+-+-+-+---+
[ # # # # # ]
SLC-------# ]--INTERNAL_BOX_TERMINATOR
[ o o o o o ]
+-----------+
# = SCSI connector SCSI-1 or SCSI-2 Type
o = Disable switch
I wonder if this is available somewhere.
If not, I possibly plug in my soldering iron and hack it together
myself.
Suggestions Welcome
Please E-mail
--
Marcel Bernards, UNIX & Net sysadm Netherlands Energy Research Foundation ECN
P.O. Box 1, 1755 ZG Petten, PHONE: (+31 /0)2246 4579 FAX: (+31 /0)2246 1864
EMAIL: bernards@ecn.nl ..!hp4nl!ecn!bernards EARN/BITNET:ESU0130@HPEENR51
SCREAMNet : AAAAAARGHH!HUH?? : Disclaimer: "The AntiChrist is the Computer !" kc@hprnd.rose.hp.com (Kurt Chan) (10/27/90)
|> 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 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? Yes, there are high-density connectors defined in SCSI-2. They are called "SCSI-2" connectors primarily because they are new for SCSI-2. The low-density "AMP CHAMP" or "CENTRONICS-style" connector and ribbon cable connector have been retained from SCSI-1. |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 "SCSI-2" terminology as applied to the connector is not intended to suggest which new SCSI-2 functionality is supported on the host adapter. |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. Correct - this is also called the "low density unshielded" connector. Note that these are not intended to be used on shielded bulkheads, but rather on devices which go inside a shielded cabinet (for FCC compliance to EMI standards). |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. AMP, Honda, and Fujitsu are the manufacturers of the high-density shielded connectors. The 3M connector that looks similar has a totally different contact style ("ribbon" instead of "tuning fork and blade"). High density SCSI cables are still quite rare, especially "off the shelf". The few cable assembly houses that have the capacity to make these in quantity will have had to invest in some fairly new tooling. |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. Try Icontec in Milpitas, CA or Tritec/Moldcon in Gardena, CA. Regards, Kurt Chan Hewlett-Packard