8 Jun
2015
8 Jun
'15
1:17 p.m.
Yeah, there were a few CDC drives like that ... I encountered a few "Hawk"
drives once on an old Alpha Micro S-100 machine long ago; I believe it
was, five megs fixed, five megs removable?
The pack was about the size of a garbage can lid and I believe the unit
spun them up to around 2400 RPM or so ...
Those are the oldest, largest magnetic disk drives I have ever seen in
operation and it was very impressive to me at the time! So loud just
running and a very definitive "clunk" from the head assembly when it
started moving!
Best,
Sean
On Mon, Jun 8, 2015 at 11:31 AM, tony duell <ard at p850ug1.demon.co.uk> wrote:
The RC25 was one of the last cartridge drives
(before fixed drives came
back in small sizes and exploding
capacity), somewhat interesting because of its
compact size, and very
odd and hard to use because the
designers threw in a fixed platter. Perhaps they
thought that it was a
good idea because it gave you double the
capacity at modest extra cost, but in practice it
made for a major pain
in the software and operationally.
Many other compainess pulled a similar trick...
The CDC 'Phoenix' (is that a 9648 or something) had a removeable pack
containing one platter and
3 fixed platters. Capacity was 16MBytes per surface (or so), so the
removeable pack stored 16Mbytes)
(one data surface, one servo surface), the fixed part was 80 MBytes (5
data, 1 servo surface).
Plessey made an RK05-a-like (same interface, linked to their version of
the RK11-D, took same
cartridges, same format, etc) with a fixed platter as well as the
cartridge. Of course the HP7900 was
like that too.
I never really liked the idea. The main problem was you lost access to the
fixed disk(s) while changing the
removeable one.
-tony