15 Oct
2015
15 Oct
'15
10:37 a.m.
Does anyone have any idea what drive/system an 8-sector decpack would have been used with?
We have a few of them on our shelves at the LCM and I can't find any reference that
mentions 8-sector packs. (Just the usual 12 and 16-sector ones.)
They're clearly labeled "decpack 1100 BPI - 8" and the sector ring marks out
eight sectors. These are RK05 (IBM 2315) style packs.
Thanks,
Josh
Sr. Vintage Software Engineer
Living Computer Museum
www.livingcomputermuseum.org<http://www.livingcomputermuseum.org>
15 Oct
15 Oct
10:58 a.m.
On Oct 15, 2015, at 1:37 PM, Josh Dersch <JoshD at
LivingComputerMuseum.org> wrote:
Does anyone have any idea what drive/system an 8-sector decpack would have been used
with? We have a few of them on our shelves at the LCM and I can't find any reference
that mentions 8-sector packs. (Just the usual 12 and 16-sector ones.)
They're clearly labeled "decpack 1100 BPI - 8" and the sector ring marks
out eight sectors. These are RK05 (IBM 2315) style packs.
Half density? I vaguely remember an RK05 style drive at half the density. RK02? Or am I
mixing it up with RP02 vs. RP03?
The peripherals handbook says that the RK05 recording density is about 2000 bpi, so 8
sectors would be 256 12-bit words at half density, i.e., half the sector slots of the
regular PDP8 pack.
paul
10:59 a.m.
Half density? I vaguely remember an RK05 style drive
at half the density. RK02? Or am I mixing it up with RP02 vs. > RP03?
No, you're right. The RK02 is the low-density drive (actually a Diablo model 30), the
RK03 being the high
density model. The RK05 has the same bit density (heck the same format) as the RK03.
There was an RK01 I beleive. I forget who made that (it wasn't DEC, if you see what I
mean), but I could
believe thst was low density too.
-tony
11:27 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony duell
Sent: Thursday, October 15, 2015 11:00 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: 8-sector decpacks?
Half density? I vaguely remember an RK05 style drive at half the density. RK02? Or am
I mixing it up with RP02 vs. > RP03?
No, you're right. The RK02 is the low-density drive (actually a Diablo model 30), the
RK03 being the high density model. The RK05 has the same
bit density (heck the same format) as the RK03.
There was an RK01 I beleive. I forget who made that (it wasn't DEC, if you see what I
mean), but I could believe thst was low density too.
-tony
That seems probable; the major reference I found was this:
http://www.ultimate.com/phil/pdp10/dec.disks
Which suggests that the RK02 is 12 or 16-sector; but it could be in error. (I've
verified via DEC peripheral handbooks that, at least on the -11, the RK02 used 12-sector
packs. I haven't yet found a handbook for the 8/I that covers the RK02 -- the one I
have on my desk here is from 1972 and only talks about the RK01, so I guess it's a bit
too early. Given the short life of the RK02, it may be tough to find the right one :).
(The RK01 is 16-sector on the 8/I, FWIW.)
- Josh
9:17 p.m.
On Thu, Oct 15, 2015 at 01:58:10PM -0400, Paul Koning wrote:
Half density? I vaguely remember an RK05 style drive
at half the density.
RK02?
Yes, RK02. But I could have sworn that it ran half-sized sectors,
not half the number of full-sized sectors. Could be wrong.
John Wilson
D Bit
3356
days inactive
3357
days old
4 comments
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participants (4)
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ard＠p850ug1.demon.co.uk -
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wilson＠dbit.com