HP 9836, HP 86 ??

ard(a)p850ug1.demon.co.uk (Tony Duell) writes: 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