The really
useless ROM Basic in old
TRS-80 Model I computers. It only gave you 26 numric
variables,
A-
Z, two
string variables
A$ and
B$ up to 16 characters long each, and one
array variable (named A, of course) that could have as many elements as you had
RAM for. Unlike newer
BASIC dialects, Level I Basic required
line numbers on every line.
Only 3 error messages exist in LeveL I Basic: WHAT? for syntax errors, HOW? for any other programmer error, and SORRY for computer errors (like running out of memory).
Level I Basic was eventually replaced (via ROM upgrade) to Level II Basic, which had many more features, variables and more informative cryptic error messages, not to mention some cool games that I want to translate to C if i ever get any free time.