Hi-Tek “High Profile”
The design was copied wholesale by Stackpole, leading to great difficulty in identifying whether a specific keyboard uses Hi-Tek or Stackpole switch grids, or a mixture of both (as found in an HP 9825A keyboard).
The service manual for the HP 85 contains the only official description so far of any means to distinguish the two products. The differences are as follows:
|Component||Hi-Tek form||Stackpole form|
|Contacts||One solid, one slotted||Both contacts identical|
|Spring, standard||28 mm (1.1″)||22 mm (0.89″)|
|Spring, space and alt. action||35 mm (1.4″)||26 mm (1.01″)|
There are at least two variants of the HP 9825 keyboard:
Unfortunately the details for these keyboards are not given in the service manual. The HP 9825 is a couple of years older than the HP 85, which may explain why the former has Stackpole switches that appear to have been directly copied from Hi-Tek, while the latter has Stackpole’s own patented design.
See Hi-Tek and Stackpole recognition on the Deskthority wiki for more details on differentiating the two product ranges.