23 Feb
2011
23 Feb
'11
2:19 p.m.
From: Mr Ian Primus
Sent: Wednesday, February 23, 2011 11:16 AM
--- On Wed, 2/23/11, Jerome H. Fine <jhfinedp3k at
compsys.to> wrote:
> From: Jerome H. Fine <jhfinedp3k at
compsys.to>
> Subject: Re: Bit of DEC Trivia
>> Guy Sotomayor wrote:
>> On Feb 23, 2011, at 9:40 AM, schoedel at
kw.igs.net
>> wrote:
>>> On Wed, 23 Feb 2011 08:25:42 -0800, Guy
Sotomayor
>>> wrote
>>>> Q: How many DECTapes (images) can fit
on a 1TB HDD?
>>> All of them?
>> YES! Finally someone got it! :-)
>> DEC never shipped millions of DEC Tapes.
> At one time, the PDP-11/44 and the VAX 780 used
the TU58 media as
> distribution tapes. How many installations existed?
Ah, but you're forgetting. TU58's aren't
true DECTapes. The TU-58 (DECTape
II) is really more of a modified DC150 format - the true DECTapes are
little round reels. They were used on PDP8 and PDP12 machines primarily.
DECtapes (originally called "Microtapes") were invented for the PDP-4, and
were used on the PDP-4, PDP-5, PDP-6, PDP-7, PDP-8 family, PDP-9, PDP-10,
PDP-11 family, and PDP-15. They were also used on Data General systems,
and the alternate format (wrapped the opposite direction around the reel)
called LINCtape was used on LINC, LINC-8, and PDP-12 systems. There were
three drives, the 555, the TU-55, and the TU-56; the latter two were used
on 12-, 16-, 18- and 36-bit systems.
Until the advent of the floppy disk, DECtape/LINCtape was common on a lot
of minicomputers, and even on mainframes.
Rich Alderson
Vintage Computing Sr. Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/