19 Feb
2003
19 Feb
'03
3:49 a.m.
Owen: the RC25 are DEC's attempt at creating funny things.
They are MSCP disks (connect to UDA50 or KDA50) with an SDI
bus. They are actually two drives in a single coffin- one
winchester drive (13MByte) and a removable cartridge drive,
also 13MB. So, one could back on the winchester to the
removable, and so on.
I have one here.. just no cartridge.
--f
-----Original Message-----
From: Owen Robertson [mailto:univac2@earthlink.net]
Sent: Wednesday, February 19, 2003 6:26 PM
To: Classic Computer Mailing List
Subject: DEC RC25 Drives
A few weeks ago, I got a rather nice PDP-11/34 (34A, turnkey
front panel)
from a scrap yard. They had two identical systems being used
in some sort of
electronic testing devices. I only got one system because the
other one
looked like it had been hit by a forklift a couple times. It
wasn't in great
shape, so I salvaged some cards from it (CPU, memory, DELUA, drive
controller, UNIBUS utility stuff...).
My system is in very nice shape though. And along with the
CPU, I also got
two RC25 drives, along with controllers and cables. I've
never seen these
before. Can anyone tell me anything about them? They look
like nice drives,
but I've never really heard much about them.
Anyway, this will be my third 11/34. Of the other two, I
still have (and
very much like) one, and one has been passed on to another
list member.
Anyway, more questions on recent acquisitions to come
shortly, I'm sure.
--
Owen Robertson
19 Feb
19 Feb
4:05 a.m.
on 2/19/03 11:45 AM, Fred N. van Kempen at Fred.van.Kempen(a)microwalt.nl
wrote:
Owen: the RC25 are DEC's attempt at creating funny
things.
Well, I would call it a success.
They are MSCP disks (connect to UDA50 or KDA50) with
an SDI
bus. They are actually two drives in a single coffin- one
winchester drive (13MByte) and a removable cartridge drive,
also 13MB.
That explains a few things, like the 'Eject' button and the write-protect
switches marked 'Fixed' and 'Removable'. I figured *something* had to be
removable. :-)
I have one here.. just no cartridge.
How do you tell if there's a cartridge in there or not? I haven't powered
them up yet.
Anyway, maybe I'll luck out and there will be an OS on there. Thanks for the
information.
--
Owen Robertson
20 Feb
20 Feb
8:15 a.m.
Owen Robertson wrote:
How do you tell if there's a cartridge in there or
not? I haven't powered
them up yet.
You will find a pinhole in the lower right section of faceplate.
With some deft manipulation of a straightened paper clip you should
be able to locate a lever which will release the front door.
One of the 2 RC25's I salvaged a few years back did have a pack in
place. Unfortunately, both drives were DOA.
-nick o
houston, TX
19 Feb
19 Feb
10:19 a.m.
"Fred N. van Kempen" wrote:
Owen: the RC25 are DEC's attempt at creating funny
things.
Jerome Fine replies:
Correction: "The RC25 WAS DEC's attempt at creating funny things."
They are MSCP disks (connect to UDA50 or KDA50) with
an SDI
bus. They are actually two drives in a single coffin- one
winchester drive (13MByte) and a removable cartridge drive,
also 13MB. So, one could back on the winchester to the
removable, and so on.
I like that analogy -
"coffin"!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The few people who provided any direct information about the RC25
stated they were the worst drive ever - by any standards for any
computer -
well, maybe for a computer that needed to use the data again (grin).
If the RC25 was used with just ONE cartridge ALL the time and
it was not turned off, then it often lasted for a week or even two.
So while the drive and the cartridge were much smaller than an RL02,
the difference in reliability was like the difference in size between an
electron and the Earth.
I have one here.. just no cartridge.
Why bother?
If you can read your media - if you have any - just read
them and back them up. Otherwise, you might want to
use the RC25 as a scratch drive for a few years to see if
your RC25 is reliable.
Sincerely yours,
Jerome Fine
--
If you attempted to send a reply and the original e-mail
address has been discontinued due a high volume of junk
e-mail, then the semi-permanent e-mail address can be
obtained by replacing the four characters preceding the
'at' with the four digits of the current year.
12:39 p.m.
To add and correct, the RC25 drive was manufactured by CDC and NOT
digital. Its 26mb fixed and 26mb removable, for a total of 52mb. Used
to have a bunch... they are NOT the most reliable things around, but
with proper handling procedures they worked...
"Fred N. van Kempen" wrote:
Owen: the RC25 are DEC's attempt at creating funny
things.
They are MSCP disks (connect to UDA50 or KDA50) with an SDI
bus. They are actually two drives in a single coffin- one
winchester drive (13MByte) and a removable cartridge drive,
also 13MB. So, one could back on the winchester to the
removable, and so on.
I have one here.. just no cartridge.
--f
> -----Original Message-----
> From: Owen Robertson [mailto:univac2@earthlink.net]
> Sent: Wednesday, February 19, 2003 6:26 PM
> To: Classic Computer Mailing List
> Subject: DEC RC25 Drives
>
>
> A few weeks ago, I got a rather nice PDP-11/34 (34A, turnkey
> front panel)
> from a scrap yard. They had two identical systems being used
> in some sort of
> electronic testing devices. I only got one system because the
> other one
> looked like it had been hit by a forklift a couple times. It
> wasn't in great
> shape, so I salvaged some cards from it (CPU, memory, DELUA, drive
> controller, UNIBUS utility stuff...).
>
> My system is in very nice shape though. And along with the
> CPU, I also got
> two RC25 drives, along with controllers and cables. I've
> never seen these
> before. Can anyone tell me anything about them? They look
> like nice drives,
> but I've never really heard much about them.
>
> Anyway, this will be my third 11/34. Of the other two, I
> still have (and
> very much like) one, and one has been passed on to another
> list member.
> Anyway, more questions on recent acquisitions to come
> shortly, I'm sure.
>
> --
> Owen Robertson
--
David Barnes
davebarnes(a)adelphia.net
OpenVMS , Tru64, Netbsd, Linux guru
and collector of DEC equipment
7977
days inactive
7978
days old
4 comments
5 participants
participants (5)
-
davebarnes＠adelphia.net -
Fred.van.Kempen＠microwalt.nl -
jhfinepw4z＠compsys.to -
oliv555＠arrl.net -
univac2＠earthlink.net