Obsolete media -- wanted a non-three phase RP06

From: Bill Pechter <pechter_at_pechter.dyndns.org>
Date: Sun Nov 28 13:57:06 1999

> Unless there is no equivalent... I've got the exact problem with the
> DECsystem-10 I got earlier this year... it came with two RP06 drives.
> They are 3-phase drives. We don't yet have three phase power (or a
> close approximation of it), so cannot run the drives. Without the
> drives, we cannot even load the microcode for the machine, so it is
> a very large paper-weight.
> I've been looking of a non-three-phase replacement for the drives, but
> we still would need three-phase to get the data off the disks I have.

Well, Megan... look no further than your RP06.
RP06's are not three phase, although the power wiring is set for three

RP06's are internally using two phase 220v motors and the third phase
is used to either (my memory is hazy)

1. power the DCL
2. power the motor in a second RP06

Two RP06's were designed to strap together with a daisy chain three
phase cable arrangement. Two wires (220) powered the motor and one of
the phases (I think) also powered the card cage. If there was a second
RP it got the unused phase and the lighter loaded of the two phases used
in the first drive.

I'm pretty sure phase 3 wasn't used anywhere in the first drive
(although it might've gone to the first DCL... anyone have prints?)

This means you can get an RP06 working in normal house/apartment wiring
if you have 220 for an electric range, clothes dryer or other
heavy appliance...

> It would be great if there was a massbus interface for a more recent
> tape drive, and the same for a disk... it would be neat to be able to
> have a DAT tape acting like a TU77 or something supported by the machine,
> and a couple of SCSI or even IDE disks acting as RM03 or RP06 disks...
> (anyone know of any? Anyone up for the challenge of designing one?)

Well, considering the DEC Massbuss patent and that they damn near sued
anyone who used it to death... I don't think it will get much interest.
I don't know any company out there that would consider it.

Perhaps someone will look at it and make an RM05 lookalike adapter
that let CDC9766's and newer SMD and E-SMD's sit on a massbus
and emulate RM05's or RP07's.

Is that Massbus patent expired yet? How long before LAT get freed up and
reverse engineered? I wonder if AMP still even makes the connectors
since they were a supposedly sole source item.

(Some German outfit I can't remember -- Braegan or something got killed
on that Massbus one in court when I was in Field Service.) They interfaced
Calcomp's to the massbus. I think Emulex got nailed on the 11/70 cache
bus as well.

> Megan Gentry
> Former RT-11 Developer

DEC unfortunately (and this hurt their business a lot in the mid-late
80's) began to think like IBM and try to close up all interfaces except
for the Unibus/Qbus.

      Three things never anger: First, the one who runs your DEC,
      The one who does Field Service and the one who signs your check.
Received on Sun Nov 28 1999 - 13:57:06 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:32:30 BST