Thanks chaps. I've been after this one too. I did manage to find a couple of years ago on the web a site which had the programming spec for this device, but I can't remember where it is now.

Also ** a free macro assembler which will work with this device (and all other MCS48 and MCS51 derivatives) called TASM is available from http://www.programmersheaven.com which also has a lot of other useful bits and peices for the micros, and also at http://www.geocities.com/Athens/Forum/5684/