Frank McConnell <fmc(a)reanimators.org> wrote:
Even in the non-HP-IL Thinkjets? I really don't
know, I've never taken
screwdrivers to Thinkjets to compare their internal architectures.
The main chip in the Thinkjet has an integral HP-IL interface. Some
non-HP-IL Thinkjet models work by adding an HP-IL-to-other-interface
converter. I'm told that some of the parallel (Centronics) Thinkjets
do not use a converter, but I haven't confirmed that.
The Thinkjet in the HP 9807A Integral (the 68K & HP-UX based "lunchbox"
machine) actually uses the HP-IL interface to talk to the main CPU
(via the standard 1LB3 HP-IL chip). They didn't bring the HP-IL out
to an external connector for additional devices, although they offered
an HP-IL expansion card.