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Beta BASIC was a BASIC interpreter for the Sinclair Research ZX Spectrum microcomputer, written by Dr Andy Wright in 1983 and sold by his one-man software house BetaSoft.〔 BetaSoft also produced a regular newsletter/magazine, BetaNews. Originally it started as a BASIC toolkit but over time it grew into a full replacement. == Facilities == Beta BASIC completely replaced Sinclair BASIC, which as common for the time was also the OS providing a command line interface (CLI). Thus Beta BASIC provided a new and improved CLI and editor. It supported Sinclair's idiosyncratic single-key entry system for BASIC keywords but also allowed keywords to be spelled out letter-for-letter. This also removed the necessity for memorising the sometimes arcane key combinations necessary to enter less-commonly-used BASIC keywords. However, the single-key entry system was also extended by mapping the Spectrum's 'graphics' characters to Beta BASIC's new keywords. To switch from keyword entry to typed entry, it was merely necessary to type a single space, causing the cursor mode to change from K (keyword) to L (lowercase) or C (capital). (The KEYWORDS statement could also be used to alter this behaviour, for example by disabling the K mode.) This was a much simpler, more elegant & less intrusive change than Sinclair's own full-screen editor for the Spectrum 128. The editor, when listing, could optionally automatically prettyprint code. It was possible to do this manually in Sinclair BASIC, but automatic indentation has the advantage of highlighting certain types of coding error - primarily those to do with failing to correctly close constructs. Other editing improvements included automatic highlighting of the current-line indicator - a small tweak but disproportionately helpful - and the ability to move the cursor up and down as well as left and right, a huge boon when editing long lines. Combined with the 64-column display (see "New functionality" section below), these improvements made Beta BASIC a much more productive environment even for coding standard Sinclair BASIC and making no use of BetaSoft's language additions. Beta BASIC was also a BASIC interpreter in its own right, completely replacing and bypassing the Spectrum ROM, which it used as a library. It occasionally made calls into the ROM to access useful functions which it was not worth re-implementing in Beta BASIC itself, either because the ROM routines were good enough or for reasons of space - Beta BASIC had to run in the 48 KB of memory available on a Spectrum and still leave room for the user's code. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Beta BASIC」の詳細全文を読む スポンサード リンク
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