Multi-platform distribution format (Was: Backups [was

Jerome H. Fine jhfinedp3k at
Mon Sep 21 16:26:12 CDT 2015

 >Jay Jaeger wrote:

>>On 9/21/2015 11:34 AM, Paul Koning wrote:
>>For RX50?  On standard PDP11s, those used an MSCP controller, which means the controller would have to do it.  Did it?  The only MSCP controller I remember that did formatting was the UDA50.
>>I suppose you could on a Pro, since that had its own particularly disgusting junk controller.  But I haven't seen RX50 formatting there.  My impression was that they came factory formatted, with the DEC-specific 10 sector per track format.
>Acch.  Bad memory cells.  This actually was discussed back in 2002.
>Some of the correspondents in that discussion are also denizens of this
>mailing list, may recall I made the same mistake back then:
>The diagnostic was/is:
>So, just to verify, I fired up my 11/23 (which hasn't been on in YEARS),
>which came right up, and inserted the floppy and booted it:
>It formats:
>RD51, RD52, RD53 on an RQDX1 or RQDX2
>RD51, RD52, RD53, RD54, RD31, RD32, RX33 on an RQDDX2
>Sorry for the confusion.
Then you have answered the question!!

But it there may be some possible confusion.  If I remember
correctly, the RQDX3 was used with the RD54 and RX33
and the RQDX2 or RQDX3 was used with the RD53.

I could be wrong, but that is what I seem to remember.

So on a PDP-11 Qbus system, it is not possible to FORMAT the
RX50 which uses an RQDX1, RQDX2 or an RQDX3.

BUT, how is it possible to FORMAT the 5 1/4" RX33  HD floppy
which uses an RQDX3 controller?

If it can be dome with the RX33, why not with the RX50?

Jerome Fine

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