VAXstation 3100 history (Was ... different)

From: <(>
Date: Wed Dec 1 07:47:16 1999

>> Yes, the first 3100's had MFM controllers, and half-height MFM drives
>> (RD31, RD32) in them. They also had a 34-pin floppy interface to a
>> non-SCSI RX23. Then came models that had *both* MFM and SCSI interfaces.
>> The latest ones had two SCSI interfaces, and used a SCSI-fied RX23 in
>> them.

> I've never seen anything more primitive than the ST506/SCSI
>controller. Was there really a non-SCSI board before that?


> Even the
>earliest production ST506/SCSI boards in my experience lacked some or
>all of the 20- and 34-pin connectors for the ST506 disks

The non-SCSI disk controller is a ST506/SCSI board unpopulated in
the *other* direction - it lacks the SCSI chip and connectors, but
has the ST506 parts. There's a plain metal flange on the rear where the
external SCSI connector would be.

There are also, of course, 3100's without any disk controller in them
at all.

> The potential of DUA0 and DUA1 explains why the RX23 floppy is DUA2.
>I always assumed that DUA3 would be the other half of an RX50, if it
>were ever supported, but that was only an assumption. The firmware on
>my 3100 systems seemed bewildered by an RX33, so I never bothered trying
>an RX50.

I never got around to trying that particular combination (though I did
have a RX50 hooked to a VS2000 - it worked fine under VMS, but evidently
the built-in firmware didn't like it.)

>> True, the RX23 doesn't have a lot of use. You can't even (officially)
>> build a standalone backup kit on it.

> I modified the V6.2 STABACKIT to build a kit on (three) RX23
>floppies, but some older firmware couldn't handle booting from them.
>V1.5 is good, possibly V1.4 also, as I recall. Faster booting than from
>a TK50. (Toggle switches would be _about_ as fast as a TK50.)

Even faster, build standalone backup on a hard drive :-).

If you want to see slow, remember the process of building standalone
backup on TU58's on a 11/750 or 11/730? We're talking most of a *day*!
No wonder we've tried to erase those times from our memories :-).

 Tim Shoppa                        Email:
 Trailing Edge Technology          WWW:
 7328 Bradley Blvd		   Voice: 301-767-5917
 Bethesda, MD, USA 20817           Fax:   301-767-5927
Received on Wed Dec 01 1999 - 07:47:16 GMT

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