Saving space, speeding up and keeping things clear
Mike Costello · 1983
The ZX81 presents a number of problems to the programmer who wishes to write BASIC programs longer than two or three K. Execution speed is very poor, far poorer than the 3 MHz clock rate would indicate, owing to a number of design features of the machine. Certain statements take up an inordinate amount of memory and even a moderately ambitious program runs the risk of filling 16K memory, thus requiring the programmer to stop and think up ways of compacting his coding in order to allow him to complete his project. When the program is complete and a copy is dumped to the printer, a great deal of additional documentation may have to be added if the programmer wants to be sure that he will be able to understand its workings at a later date. The purpose of this chapter is to give advice on these three topics so that programs can be designed from scratch to minimise such problems.