Derek Thomas wrote and sold under the name Forth Dimension hoping to emulate the success of those who were writing games programmes for the ZX80 and ZX81. He fitted his Jupiter Ace into a metal box with a home made keyboard from components bought from Maplin Electronics. Derek also used a Downsway Jupiter 48K ram pack and double adaptor card so the ram pack and ZX printer could be used at the same time.
Adverts in Popular Computing Weekly 17-23 February,1983,
also in Popular Computing Weekly 24 Feb, - 2 March,1983 issue.