On Wed, 5 Jan 2005 09:45:00 -0500, Paul Koning
wrote:

>>>>>> "Ashley" == Ashley Carder writes:
>
> Ashley> A couple months ago I acquired a new, still in the plastic
> Ashley> wrap, still in the box, never opened disk pack that at first
> Ashley> glance appeared to be an RK05. I finally decided to look
> Ashley> further at it to see if it was a 12 sector or 16 sector RK05
> Ashley> pack, since it had no identifying label or markings.
>
> Ashley> Upon further inspection, I found that it did not have the
> Ashley> usual rim on the hub, where normally you would be able to
> Ashley> count the thin notches to determine whether it was a 16
> Ashley> sector or 12 sector RK05. Instead, it has a short, rounded,
> Ashley> unnotched rim where normally it would have the tall thin rim
> Ashley> with notches. Otherwise it looks just like an RK05. The
> Ashley> case is interchangeable. I actually took it apart so I could
> Ashley> use the case on another RK05 pack that had a decent platter
> Ashley> but a bad outer case.
>
> Ashley> What is this thing? RK03?
>
>I have no idea, but here's a far out thought... some IBM 360
>mainframes (the 360 model 44 for example) have an RK05 style drive in
>them. Reading the 360 model 44 functional description (on
>bitsavers.org) suggests that probably isn't right -- that disk (Model
>2315) is described as having 16 fixed size sectors. Hm, that would
>mean an RK08 pack would fit???

Could be - some IBM systems did use Diablo-type RK03'-type drives.

Shame you recycled it - it's much harder to find these IBM packs than
the DEC items, especially new ones!!!

Mike
--
http://www.corestore.org
"All I know is that I'm being sued for unfair business practices by Microsoft. Hello pot? It's kettle on line two" -
Michael Robertson

Paul Koning wrote:
> Ashley> sector or 12 sector RK05. Instead, it has a short, rounded,
> Ashley> unnotched rim where normally it would have the tall thin rim
> Ashley> with notches. Otherwise it looks just like an RK05. The
> bitsavers.org) suggests that probably isn't right -- that disk (Model
> 2315) is described as having 16 fixed size sectors. Hm, that would
> mean an RK08 pack would fit???

IBM 2315 disks were introduced with the IBM 1130 and have 8 hard
sectors. The disk pack with the unnotched rim could be a HP disk pack
for the 7900 series disk drives (e.g. 7905 or 7906). They are completely
soft sectored and use a servo surface on the fixed platter (in the
drive) for positioning. Otherwise they look just like a RK05 or IBM2315.

Christian