Entering (and losing) programs on HP 48

[Steve Simpkin]

(01-12-2021 01:37 AM)calculon Wrote:  After years of using HP calculators for simple tasks I've decided to take the plunge and learn how to program the HP 48, starting with the information in the HP 48 Owner's Manual. But I've hit a snag. One program from this book that I've definitely keyed in correctly can't be put on the stack because of an "Invalid Syntax" error. This means losing the work... or does it? I'd be very surprised if the calculator can't save a partially or wrongly entered program but I can't find anything in the Manual or online to enlighten me. (The program that I've now typed in and lost twice is BDISP on p. 31-10. The error comes at the very end, before PRESERVE that was previously entered successfully.)

Typically when you get an "Invalid Syntax" error when entering a program, it will leave the faulty program on the entry line with the offending syntax highlighted so you shouldn't lose the entry unless you press ON twice to delete it. If you can't find the error and you want to save the entry for later, put quotes around it and enter it as a string on the stack. You can leave it on the stack or save it as a string in a variable. Later when you want to edit it again, recall it to level 1 on the stack, press the down arrow to place it in the command line and remove the quote marks.