Biggest drawback of Poqet Computer Corp’s credit card-size memory cards is the price – the RAM versions cost about $1 per Kb – and as much as $1.50 per Kb with the small capacity ones, and the ROM cards will cost software developers $50 a time so that that will have to be added on to the cost of the applications; the advantage of these is that the program executes directly from the ROM rather than loading into main memory, so that the internal memory will go further; for software developers, a benefit is that the programs can’t be copied.