Real ZX80 BASIC

Bywater BASIC is similarly basic to Sinclair BASIC, but the two certainly aren’t the same. Perhaps most importantly, the first version of Sinclair BASIC supported only integers. This major limitation set it aside from most other dialects of BASIC, and also from later versions of Sinclair BASIC that shipped with the ZX81 and the ZX Spectrum.

Bywater BASIC is also one step ahead of Sinclair BASIC in taking the first few steps towards structured programming. Interestingly, though, Sinclair BASIC had a few additional instructions of its own. While Bywater BASIC supports pixel graphics, Sinclair BASIC was able to display primitive graphics by writing characters from a special character set to specific screen locations.

Because some of Sinclair BASIC’S extensions related to aspects of the ZX80 hardware, for example screen modes and character sets, one of the best ways of seeing it in action is via a ZX80 emulator. One of the easiest to use is at www.zx81stuff.org.uk/zx81/jtyone.html, and it runs in a browser. Strictly speaking this is a ZX81 emulator, but it has a lot in common with the ZX80.

If you want the genuine 1980s experience, search out some Sinclair BASIC game listings and type them in yourself. You might struggle to understand some of the listings, though. Many of the BASIC games did a lot of the clever stuff in machine code, to achieve adequate speed, with the BASIC program doing little more than writing that code to memory and executing it.