HP-110 Plus laptop power supply specs?

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Mon Jun 28 17:18:38 2004

>
> At 09:45 PM 6/27/04 +0100, you wrote:
> >It's 8V AC (so there's no pinout information as such) from a 3VA
> >transformer of some 11 ohms internal resistance (and yes, that is
> >important according to the technical reference manual which I happen to
> >have).
>
> So like some HP calcs the adapter only charges the battery, it won't run
> the machine with a dead/missing battery.

Actually, I have an idea that the 110 and Portable+ will run from the
adapter with no battery installed. I am not sure if they're supposed to
do this though.

>
> As I expected the battery pack is totally dead. I doubt I'll bother
> replacing the battery. I've never seen these cells at any of the usual
> electronics suppliers around here. I don't doubt that one of the
> specialist battery companies has them, but their prices are too rich for me.

Last time I bought some they were about \pounds 5.00 each for the cells.

> I had it running for a while earlier today. Everything seems to be working
> as it should. Nothing out of the ordinary beyond the QWERTZ keyboard and
> PAM being in German. The only application installed in MS-Word, which is

There's a configuration EPROM -- a 27C64 IIRC -- mapped in the
processor's I/O space that determines things like the keyboard layout,
machine memory size, hard reset defaults, etc. The TechRef gives the
format of said EPROM if you want to make changes, etc...

> English.

You'll find 2 drawers under the machine, one each side, held in by a
couple of Torx-head screws. One is almost certainly a 'software drawer'
(holds EPORMs), there other might be a RAM drawer if you're lucky. Note
that both spaces must contain something for the machine to boot -- HP
made dummy drawers that shorted the right couple of pins on the connector
together if you didn't have the 'real' drawers.

Somewhere I have details of the format of the EPROMs for the software
drawer. It's similar to an MS-DOS filesystem. I think I even have a
program to burn your own files into EPROM to put in the drawer.

-tony
Received on Mon Jun 28 2004 - 17:18:38 BST