Bank Switching for the ZX81

There was a time when 64K of memory was more than enough. No longer is this true and a common complaint heard about small computers like the ZX81/TS1000 and the Commodore 64 is that their memory is too limited and that the computers are therefore unsuitable for “serious applications”. The problem is particularly acute for the ZX81/TS1000 in which the active BASIC program area is limited to the region between 16K and 32K because of compromises made in the hardware design.