22 Dec
2025
22 Dec
'25
5:44 p.m.
I used DEC for years, from straight -8 and the11/45 at OMSI west lab, to
Metheus BSD 4.1/4.2, Sys V and RT-11 to the 90's with microvax, Those were
the days when it actually felt like you helping humanity, making life
better. Not any more.
On Mon, Dec 22, 2025 at 7:43 AM Nadav Eiron via cctalk <
cctalk(a)classiccmp.org> wrote:
Nope. Those are different drives. Mine has 2
*physical* RK05 drive IDs
for each platter. Look at (PDF) pages 12-13 in this file:
http://www.bitsavers.org/pdf/plessey/peripheral/Plessey_Minicomputer_Add-On…
I believe you're describing the PM-DD/11B and I have the PM-DD/11C. I have
them on a PDP-11/45, so OS/8 isn't part of the equation :)
Nadav
On Mon, Dec 22, 2025 at 12:48 AM Christian Corti via cctalk <
cctalk(a)classiccmp.org> wrote:
On Thu, 18 Dec 2025, Nadav Eiron wrote:
I have such a drive connected to an 11/45.
It's branded as Plessey. The
drives are double density RK05 compatible (i.e., it's like an RK05F + a
"removable RK05F" with a specially marked removable pack that looks
We have a couple of those, all branded as Plessey, but they are Wangco
type F drives. They have one fixed and one removable platter.
It is like two RK05, not RK05F.
physically like an RK05 pack) and present as 4
RK05 drives to the
controller - two on the fixed platter and two on the removable one.
Haven't
This would be on the PDP-8 / RK8E where each platter is divided into two
parts because OS/8 can't handle as many blocks as one entire platter has.
This makes your 4 logical drives, but it is still only like two RK05
drives.
Christian