> On Dec 17, 2025, at 4:29 AM, Jim Davis via cctalk <[email protected]>
> 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
