If you take the top cover off the CDTV there is a jumper just below the left hand air vent that you can remove to disable the CD drive and free up the memory used.
I remember adding a switch, passing the wire through the air vent to disable the drive to play formula 1 back in the day :-)
At the time I was so gutted after buying the CDTV then finding out It didn't play some 1mb games (aka F1) Luckely a mag revealed the jumper tip. I almost took it back to Dixon's because of this btw! :-o
