Anyone got any pins to spare, I only need one ?

Seriously though I need another input,a simple button
(setup: 16c84 LCD=6pins, three outputs, three buttons, and a sensor)
and yes I do know lots of ways to get more inputs.

However how about Mchip giving us a simple solution
to an all too common problem, Tri state inputs.

For example the 12c508 is using the 16c54 core
only 6 I/O's portA and portB inputs could be connected in parallel
with thresholds of 1/3 and 2/3 VCC
Not only double the inputs but also software configureable schmitt or
window detector are two of the most obvious uses

Taking this one stage further the outputs could also be paralleled,
open source on portA and open drain on portB and no tris registers
(I am not sure of the usefulness of this except it might be easier
to make the revisions. I mean you could simply parallel the ports,
shift the reference to 2/3 VCC for one port's inputs,
remove the pulldown fets from one port and the pullups from the other)

On the 13 I/O PIC's portA 5,6,7 could parallel with portA 0,1,2

I realise that this would need a major revision but would certainly
make the smaller PIC's more useful. More power with less pins,
isn't that what it's all about ?

Am I alone on this ?
--
Peter Cousens
email: peter@cousens.her.forthnet.gr  phone: + 3081 324450, 380534
snailmail:  Folia, Agia Fotini, Karteros, Heraklion  Crete, Greece.