TI-99/4A FAQ: Extended Basic

Extended Basic Module from Texas Instruments

  • The Extended Basic module was not included with the console and was semi-expensive originally. 
  • Extended Basic exists in two distinct versions, Version 100 and Version 110. To determine which you have us this small program:
      • 10 CALL VERSION(A) :: PRINT A
    • Only a very small handful of the earlier Vn 100 were sold. 
    • Principal difference is speed: Version 110 is much faster.
    • Version 110 fixes bugs and supports sprites and features on the 4A that were not available on the 99/4
    • EXTENDED BASIC is a much larger language than TI Basic.
    • The increase in operation speed is not shown by magazine ‘bench tests’ which use very short specific programs. In a typical program you will find the program runs in about 30% less time. Line transfers and screen handling are particularly faster than in TI Basic. This is due to the fact that some of these routines are in assembly language in Extended Basic while TI BASIC is 100% GPL. 
    • Extended Basic also adds any new commands and functions over TI BASIC enabling better use to be made of limited memory, and also permitting friendlier programs to be written.  
    • Extended Basic allows for multiple commands per program line using  :: as a command delimiter
    • Extended Basic supports the 32k memory expansion allowing 24k to be used for program data, the rest of the memory is used for stack.
    • Many TI BASIC programs can be loaded in Extended Basic, and will then run faster.
      • Exceptions are:
        • TI Basic programs over 12k cannot be loaded due to lack of memory. (memory expansion doesn’t help with this due to TI BASIC programs load into VDP ram only)
        • Some TI Basic programs will load but cannot RUN due to lack of memory.
        • TI Basic has two extra character sets: if these are used, they will produce a BAD VALUE error in Extended Basic. Extended Basic uses the memory saved by dropping these sets (15 and 16) to produce the Sprites
        • Extended Basic manual: https://www.digitpress.com/library/manuals/ti994a/ti%20extended%20basic.pdf

Versions and variations on Extended Basic:




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