Custom Menus on High-End RPL Machines

[Raymond Del Tondo]

(04-03-2019 05:51 AM)Werner Wrote:  Thanks for that explanation, Raymond.
How does the 42 handle garbage collection, then? It never seems to pause in any noticeable way.

Cheers, Werner

As far as I can see, the garbage collection works in the same way as on the other RPL machines, which also includes the 17B(II) and the 19B(II) .
Creating objects consumes RAM as in the other RPL machines, and therefore the GARBAGECOL is invoked when there's not enough room for creating the new object.

One of the differences to the HP 48S series is that in the 42S, the memory layout is somewhat less complicated due to the lack of ban switching. Less memory is moved since the user stack (list of pointers) is of fixed size, the stack objects are real numbers in most cases, whose pointers have designated system RAM addresses, so expanding/shrinking of the internal data stack pointer list happens less often.
The user stack objects are not on the data stack normally, but recalled from the designated data area when needed, operated upon, then stored back into the location.