[Simh] RB09 == RD10

[Timothe Litt]

On 27-Feb-16 08:23, Bob Supnik wrote:
> Max Burnet gave me a pointer from some old price lists, showing that
> the RD10 had very similar specs to the RB09. The RC10 manual confirms
> it - same BCD addressing of tracks and sectors, same number of tracks,
> same sectors per track, same words per sector (32 x 36b for the RD10,
> 64 x 18b for the RB09). So the "RD10s" on some PDP-9s in the services
> listing are actually RB09s, at least at the drive level.
>
> I still don't know what an RC09 is. Alternate name for an RB09?
> Half-sized variant? Another mystery is who made the actual drive
> mechanism. It precedes DEC's first internally designed fixed head
> disk, the RF09/RS09, by two years.
According to the option module list, the RC09 is a "Control for
Burroughs Disk"  The design engineer was J. Milton.

That makes sense, as the RC10 was the PDP10 controller for disk and drums.

FWIW, Family members: the RD10 was made by Burroughs.  The RM10B drum
was by Bryant.  SW documentation was removed from the PDP-10 doc set in
the 80s, but as I wrote previously, I believe the tech manuals are on
the FS microfiche.  The section with the red stripes on top.

The drums were notoriously unreliable.  Especially the ones in the Mill,
though things improved when someone realized that they tended to crash
when semitrailers bumped into the loading dock above them....

There is some documentation in an old copy of a TOPS-10 manual that I
have, but it's too fragile to scan with the equipment that I have.  Some
copies of the software notebooks kept the pages when they were updated,
but most didn't.

I snapped some pictures with a digital camera - they're not great, but
they are legible.  Buried in the -10 details are the statements
confirming the manufacturers, and you can see the BCD addressing.  The
text interleaves the descriptions of the disk and drum.

I put the snapshots here for now:
https://drive.google.com/file/d/0B2g2SW-v7RFZWk1mR1REbjBHalU/view?usp=sharing



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