[Simh] RB09 == RD10

[Timothe Litt]

On 27-Feb-16 14:19, Bob Supnik wrote:
> Thanks, Tim. Burroughs made a lot of fixed head disks at the time. I
> can't identify the model, but the IA2 (see page 7-4 of the B6700
> Hardware Handbook, on bitsavers) seems like a possibility. It has 7552
> sectors per surface vs 8000, but Burroughs sectors were longer than
> DEC sectors (180 x 8b = 1440b vs 32 x 36b = 1152b), so perhaps DEC
> format had more sectors per track.
>
> While the 18b- and 36b-groups used the same disk buyout, they went to
> different vendors for drums. The Type 24 and RM09 came from Vermont
> Research; the RM10B from Bryant.
>
> /Bob
>
> On 2/27/2016 12:00 PM, simh-request at trailing-edge.com wrote:
>> Message: 3
>> Date: Sat, 27 Feb 2016 09:31:59 -0500
>> From: Timothe Litt<litt at ieee.org>
>> To:simh at trailing-edge.com
>> Subject: Re: [Simh] RB09 == RD10
>> Message-ID:<56D1B35F.3040206 at ieee.org>
>> Content-Type: text/plain; charset="utf-8"
>>
>> 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....
>
I think this is confusing due to the hierarchy/bundling.  It's not
complicated,
I think :-)

Summary:

RB09 = RC09 + RD10.  (-A for 50 HZ)
            Probably salable part number.

RC09 = Controller
             Probably not salable, except perhaps as FS spare.

RD10 = Drive
             Probably not salable, ditto

FS probably used the controller on the contract rather than the bundle. 
They did that
a lot. Remember that these early drives each had a dedicated
controller.  Later (e.g. Massbus
disks), they'd be listed separately.  Or the first drive + controller
had a part number,
add-on drives would be listed separately.   But in this timeframe, which
they picked
was arbitrary. 

FWIW, in this case, the FS list indicates that the RC09 shipped much
later than the rest
of the system.  The system shipped in july 65; the RC09 in jan 69.

One other bit of trivia from the OML - the RB/RC09 went status 6 in July
of 71.  (6 = Obsolete, but
can still be built.)  "TPL" = "traditional products line"; I think they
were in Salem NH at that time.

Supporting data:

The (1974) OML edition that I have lists the RB/RC09 & RD10.  The 'C'
would indicate controller
(thanks to Dick Best's semantic part number scheme.)    I would guess
that RB decodes to
"Rotating magnetic memory", Burroughs" :-)  The coding got more creative
as time went
on as the "good" letters were used by early products.  (E.g. RK for
"Rotating Kartridge disk")

There is also an entry for the RB09 and RB09-A - listed as "RC09 & RD10"
and "RC09 & RD10-A"
The -A are 50 Hz versions. 

There are RC controllers for the 7, 9, 10 & 11.  (The RC11 references
the RS64 "65K 16 bit DEC DISK".)







-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20160227/56999322/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: fddheadb.png
Type: image/png
Size: 29703 bytes
Desc: not available
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20160227/56999322/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: hjfefdfe.png
Type: image/png
Size: 19862 bytes
Desc: not available
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20160227/56999322/attachment-0003.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4994 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20160227/56999322/attachment-0001.bin>