I am looking for a reference I can use to look up syntax for BASIC. The code is used on an old HP-85, which may affect the command list. I've had issues using Google because every time I search for something like "<> basic command" it thinks I literally mean basic and returns a bunch of introductory tutorials for other languages. I'll also accept an explanation for <> as an answer, below is the line which uses this.
IF X <> 700 THEN 5462. How does this decide whether or not to go to line 5462?
<> means "not equal to" in BASIC and is analogous to the != operator in most other languages. To answer your example, this would only go to line 5462 if the variable X was anything other than 700 (ie it would always goto 5462 unless X was equal to 700).