HP 9836, HP 86 ??

From: Frank McConnell <fmc_at_reanimators.org>
Date: Sat Jul 12 23:26:41 1997

ard_at_p850ug1.demon.co.uk (Tony Duell) writes:
> The HP86 is basically an HP85 without the built-in monitor,tape drive,
> or printer, but with GPIB as standard. The 9121 is a single-sided version of
> the 9122 if that's any help.

There are two flavors of HP 86, the 86A and the 86B.

The 86A does not have the built-in GPIB (aka IEEE-488 aka HP-IB).
Instead it has three connectors on the back. All three look the same,
like Centronics printer connectors but maybe with screw-downs instead
of ears. One is for a cable to a Centronics-ish printer. The other
two are for cables to external 5.25" floppy drives.

The 86B does away with all this and instead has an HP-IB connector.

Re: the 9121: yep, single-sided Sony stiffy drives that hold about
300KB I think. It's been too long and I have forgotten just about
everything except that the single-sided ones never seemed to hold
quite enough (this on HP 150s).

HP was an early adopter of the Sony 3.5" stiffies, back when it was
not clear that the 3.5" format was going to be the winner from the
several sub-5.25" media.

You know how 3.5" drives open the metal slider so they can get at the
medium? The very earliest drives didn't, and the stiffies didn't
spring-load the slider -- it was up to the user to slide the slider
before insertion into and after removal from the drive.

For a while there were goes-either-way stiffies: slider spring-loaded
so that they would close on eject from an auto-open drive, but also
with a catch so you could slide the slider over to the left before
insertion into a non-auto-open drive, then pinch the corner after
removal to release the catch and let the spring pull the slider
closed. That is why those stiffies have the legend "PINCH" near that
corner.

I don't know how pervasive these early drives were. The place where I
worked at the time had a few 1983-dated pieces of equipment (a 9121,
some 9133XVs) that were the auto-open variety.

-Frank McConnell
Received on Sat Jul 12 1997 - 23:26:41 BST