Sinclair BASIC

Sinclair BASIC is a dialect of the programming language BASIC used in the 8-bit home computers from Sinclair Research, Timex Sinclair and Amstrad. The Sinclair BASIC interpreter was written by Nine Tiles Networks Ltd. Designed initially to run in only 1 KB of RAM, the system makes a number of decisions to lower memory usage. This led to one of Sinclair BASIC's most notable features, that the keywords were entered using single keystrokes; each of the possible keywords was mapped to a key on the keyboard, when pressed, the token would be placed into memory while the entire keyword was printed out on-screen. This made code entry easier whilst simplifying the parser. The original ZX80 version supported only integer mathematics, which partially made up for some of the memory-saving design notes which had negative impact on performance. When the system was ported to the ZX81 in 1981, a full floating point implementation was added. This version was very slow, among the slowest BASICs on the market at the time, but given the limited capabilities of the machine, this was not a serious concern. The low speed was not mainly due to an inefficient interpreter though, it was an effect of the fact that 70-80% of the machine cycles were consumed by the video hardware. So the Z80 in the ZX81 clocked at 3.25 MHz was "in effect" running at well below 1 MHz from the perspective of the BASIC system. Performance became a more serious issue with the release of the ZX Spectrum in 1982, which ran too slowly to make full use of the machine's new features. This led to an entirely new BASIC for the following Sinclair QL, as well as a number of 3rd-party BASICs for the Spectrum and its various clones. The original version continued to...