17 Dec
2025
17 Dec
'25
10:09 a.m.
On Dec 17, 2025, at 4:29 AM, Jim Davis via cctalk
<cctalk(a)classiccmp.org> wrote:
Yep, I had a few. The other platter sits under the cart, fixed, but using
the same spindle air handling and actuator. I don't remember if the RK05
had the extra fixed platter. I think not.
No. The only DEC drive that had removable plus fixed on the same spindle was the RC25. I
remember when RSTS added support for one of those to be your system disk. Having to spin
down the system disk in order to swap out the removable cartridge required some
interesting OS magic. (Basically, it had to freeze things while you did the drive spin
down/up sequence.) Supposedly we did that work because we had a big customer who wanted
to put one of those systems on each of their submarines. :-)
There was an RK05F, I think, but that was just an RK05 with the cartridge permanently
installed as far as I remember; not the schizoid drive like the RC25.
By the way, on the possibility of using those packs on other drives: RK05 has 12 sector
tracks, so 12 sector slots not counting the index slot. I thought I saw 12 but someone
said 8, if so those packs would be incompatible with the RK05.
Some vague memory says that the IBM 360/44 had a 16 sector pack, but I may be confused
with the RK08.
paul