Date   : Fri, 19 May 2006 18:59:03 +0100
From   : Sprow <info@...>
Subject: Re: RAF Beeb?

In article <446DCABF.5080605@...>,
   Jules Richardson <julesrichardsonuk@...> wrote:

[snip luggables]

> Related question: how many potatoes would be needed to run a mini-B? 
> (possible fun museum display!)

MiniB takes 170mA idling (most of which is lost as heat in the 6522 and
6502!) though I've never measured it with a 65C02 in place.

The LCD is an additional 100mA, more if you have a backlight I suppose. the
last PS/2 keyboard I measured was ~60mA, but we can live without that for a
museum display.

Depending on which electrode metals you choose I'll assume 1.2V per cell, at
least 4 cells in series will be required to get to 5V -10%. Best evidence I
can glean from the internet suggests about 20uA for a nice firm spud.

So you'd need roughly  4 * (270mA/20uA) = 54000.

I'm not volunteering to peel them, but I can offer them for sale!
  http://www.sprow.co.uk/bbc/minib.htm
Sprow.