Date   : Sat, 26 Jun 2010 14:29:10 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: What's this?

> Afternoon everyone! I hope everyone is enjoying the weather!
>
> Could someone possibly identify this for me?
>
> http://www.danceswithferrets.org/bits/wotsthis.jpg

It's a Solidisk 4MEG upgrade board

http://acorn.chriswhy.co.uk/8bit_Upgrades/Solidisk_4Meg.html

There were different revisions but they all did the same thing. 4MHz CPU 
with it's own RAM, allows the CPU to run faster when accessing onboard ROM 
or RAM, like the way the Turboupgrade for the Elk.

Mark.