Term for feature that abstracts RPN program location?

[Didier Lachieze]

(05-13-2020 07:17 PM)Orome Wrote:  My question is simply: What is the name for the feature that creates the illusion that programs have no storage-spatial relationship to one another, specifically in the context of moving from say the 34C to the 41 series (e.g., "the 41 series adds ??? which previous HP calculators lacked").

As already mentioned by hth above, the closest I can think of to answer your question is "independent program spaces", and btw this is how the designers of the 41C described it in the HEWLETT-PACKARD JOURNAL - MARCH 1980 Volume 31 - Number 3, page 10 (emphasis is mine):

Quote:Local versus Global Labels

In the HP-67, each time a user label is referenced by a GTO or GSB instruction, a linear search is made through the entire user program memory to find the label. The time spent searching for labels often represents a significant fraction of the execution time for HP-67 programs. On the HP-41C, several techniques have been used to minimize label search time. The HP-41C has two classes of labels: global alpha labels and local numeric labels. The END function on the HP-41C is used to divide user program memory into independent program spaces. When a reference is made to a local label, the search for the label is conducted only in the current program space, thereby shortening the search time. Once the target label is found, its location is stored with the GTO that referenced it; in other words, the GTO is "compiled." The search is eliminated altogether on subsequent executions of the GTO function if the program has not been edited in the meantime. Global alpha labels are used for references across program space boundaries. The alpha label chain described above serves to speed up the search for global alpha labels.

The concepts of global versus local labels and separate program spaces, although not new to computer programmers, are important advances for a programmable calculator. A user can always write a new program without worrying about what numeric labels have been used in programs already in the machine, simply by creating a new program space. Users can similarly exchange and use each others' subroutines without regard for conflicting numeric labels. Moreover, the global alpha labels used to name programs can be up to seven characters in length, long enough to be meaningful and memorable.