Editing and adding programs on an HP15C

[Johnh]

A bright idea:?

After the end of a routine, after the last RTN line, add a series of 0's to get the line numbers up to one before the next multiple of 50. So the following routine always starts at a multiple of 50 or 100, and the gaps between are all zeros and can be seen as such when encountered. There's plenty of spare lines available to waste a few by doing this.