How many of you like HP41C calculators?

From: Holger Veit <holger.veit_at_ais.fhg.de>
Date: Tue Nov 18 02:56:45 2003

On Mon, Nov 17, 2003 at 12:26:48PM -0600, Ron Hudson wrote:
> On Monday, November 17, 2003, at 11:03 AM, Holger Veit wrote:
[...]
> > I once had the wild idea to obtain a defective calculator and replace
> > the PCBs with a new one, for instance with an ATMEGA on it that
> > provides
> > a complete emulation of the original machine. This would probably not
> > just mean a double speed HP-41, but a much faster beast, with the
> > original
> > look&feel.
> >
> > Besides that even defective HPs meanwhile sell like hell, I am just
> > lacking enough time for such a project :-(
> >
> > Holger
>
> Replacing the insides of a 41 would be some feat for the home hobbyist..
>
> I see a ribbon cable leading to a heavy black box on the floor... :^)

This is a mailinglist where people still know about SSI TTL and maybe
even vacuum tubes to be used in computers, but this doesn't mean that
such a hardware emulation would have to be built up with tons of SN7400s :-)

The HP41 is rather moderate in speed, with a clock of 300kHz and an
instruction cycle length of 56 bits, so it is no problem at all to
write a precise emulator with one or two modern microcontrollers
(you wouldn't just take the lowest level choice like a PIC which is
too inferior for this, but maybe a 16 bit controller like an MSP 430).

Interfacing to the existing hardware might be tricky, but, heck, HP's
engineers managed to do this more than 20 years ago as well, without
GHz processor technology.

Holger
Received on Tue Nov 18 2003 - 02:56:45 GMT