HP-71 BASIC funny quirks

[Valentin Albillo]

J-F Garnier Wrote:The HP BASIC program lines are not directly readable, they are in token form, moreover the numeric expressions are stored in an internal RPN form.

The earlier HP-85 computer's BASIC dialect did exactly that, tokenized keywords and algebraic expressions internally converted to RPN-like form upon entering the line, and stored that way, to be converted back to algebraic form upon listing or otherwise outputting the line as text.

This gave problems at times because of the reconstructed line (de-tokenized and with expressions converted back to algebraic form) not exactly matching what you entered, and also because the restored lines typically used more bytes, which could cause Insufficient Memory-like errors while listing the lines in situations of very low memory available.

Quote:The benefit of the tokens and RPN forms is a more compact and faster executing code.

Yes, and I was delighted when I got my SHARP PC-1211 back in the early 80's and saw that it tokenized the keywords so that INPUT or DEGREES, say, would only use 1 byte of RAM instead of the 5 or 7 required by the usual BASIC dialects of the time.

The tokenization also meant faster program execution, and SHARP pointed out the memory advantages in their brochure "Con memoria equivalente a 4 Kbytes" (i.e. you could do with the built-in 1.4 Kbytes what would require 4 Kbytes using non-tokenizing BASIC dialects.)

Regards.
V.