ra81's are irking me
henk.gooijen at oce.com
Thu Nov 9 01:59:41 CST 2006
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Bill Pechter
> Sent: donderdag 9 november 2006 3:53
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: ra81's are irking me
> I think (It's a long time since my '86 DEC Days...) there was
> one of the cables between the drive and the cabinet that was
> kind of null modem'd.
> This could be the problem if at one time the drive was direct
> cabled to the UDA and is now going through one cabinet->
> drive cable without the corresponding Cabinet--> uda cable hookup.
> Been a long time... I could be wrong. If there's an extra
> cable in the wiring try to just eliminate it.
> (I assume the correct drive number's on the drive select plug etc.)
Never heard of an SDI "null-modem" cable! It makes sense however,
as you normally need an *odd* number of cables between the UDA and
the RA8x drive. Since the (red) cable has a different connector at
the UDA side, you often need 2 cables to get to the drive. But that
does not work as you have to get a *third* cable. That "null-modem"
SDI cable would come in handy!
I have not had problems with my RA81 (till now, but it's been a year
that it ran for my 11/44). Like Jay, I have some six RA81's.
One recenty booted VAX-VMS on the VAX-11/750, so that one is fine.
The other 4 ... never had a look! Same goes for the RA60 ...
I always wanted to measure an SDI cable to understand why you need
three of them to get it working... Perhaps Bill has the answer,
I never got round to check them, yet.
Anyway Jay, if it worked before you moved things around, you either
had hardware (HDA, boards) that were about to fail, one of the
cables was "old", perhaps bent a lot and using/moving it developed an
open wire in it, or perhaps a loose connection?
Try some other cables if you have them.
Depending on which cable you connect (the RA81 drive has two, correct?)
you connect to port A or port B. If port A is not responsive, connect
the UDA to the other drive cable. Now port A is connected and port B
is "off". Also possible, if port A *is* connected, check the bulb in
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