Re 480z Hi Jules As far as I know the metal case was an inner London education authority variant (ilea). At that time every piece of electronic equipment used in the authorities schools was retro fitted with huge "child proof" casing. This meant that every electronic item had ugly GLC boxes fitted before we could use them. The 480zs were issued to all ILEA schools in this form in the early 80s. I remember using them at that time and wishing we had the BBCs. The rumour was that they'd done a deal with RM. Hope you don't mind me contacting you like this. You email came up on a search I'd put in for the 480z Andrew Sent from my iPad