HP-12C erase program steps

[x34]

Is there any way to erase program steps in HP-12C to free memory besides CLEAR PRGM?

Could not find info in the manual.

[Katie Wasserman]

No. You overwrite program steps when editing programs on the 12C. If you're looking to free up only some memory that was used in a program so that you can have more cash flow registers, you're out of luck. You have to erase all program steps.

[x34]

It's a pity. Katie, do you know simple way to read HP-12C flags programmatically (i mean BEGIN/END and DAY format).

[Michael de Estrada]

Wow. That's a major deficiency in this calc's programming capabilities. I've never given it any thought, since I've never programmed my HP-12C. I simply assumed it worked the same as my HP-15C, which I programmed a lot, but now I can see the difference, since the HP-12C lacks the back arrow (<--) keys that the HP-15C uses to delete displayed entries. It also means that if you make a mistake when keying in an entry, you cannot backspace over the incorrect digit to correct it, and must clear the entire entry and enter the entire line again.

[x34]

Quote:

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It also means that if you make a mistake when keying in an entry, you cannot backspace over the incorrect digit to correct it, and must clear the entire entry and enter the entire line again.

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Michael, it s much worse. You can't clear entry. Only overwrite it.
If you skipped one program line during programming, you should start with the line and enter all lines following.
I think it is the last RPN HP calculator (may be shares this feature with HP-10C) without insertion/deletion. HP-20S and HP-21S have this annoying feature too, but they are not RPN.

[Katie Wasserman]

The 20s and 21s have insert/delete editing I think.

I've concluded that the reason why the 12C (10C, 25, 38e/c, others?) don't have insert/delete editing is becasue there are no labels. You can branch to any program line number. To make for a easy to use programming environment insert/delete would have to re-assign all the goto/gosub targets each time you deleted or inserted a step. This would likely create an unacceptable delay on the original 12C (and the others) and it also would require the programmer to keep looking around for the new target location if it were needed for further entries/edits.

Personally, I think that they should have allowed insert/delete editing and let the user reassign branches as needed. That's not more difficult than the suggested method of adding branches out of the code stream then back in, when you want to insert additional code.

-Katie

[x34]

Quote:

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The 20s and 21s have insert/delete editing I think.

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May be. I do not have it at hand. So, i'm wrong.

Edited: 11 Feb 2011, 12:03 p.m.

[Bart (UK)]

For interest:

Now that I have had opportunity to take out my 20S, it has Label and line Insert/Delete (with auto renumber) functionality. Unlike the Voyager calculators, the 20S has fixed 99 line (merged keystroke) program memory that is not shared with its 10 registers.