Virtual Register Table?

[DavidM]

I often use Nosy 4.1 to look at how built-in commands on the 49-50g are implemented, as there is much that can be learned in seeing how the code was constructed by the original authors.

While reading through the Nosy documentation today I came across this reference to something that I don't think I've seen before:

Quote:(Nosy4.1.txt, in the section marked "Tables")
"There are many tables in ROM that Nosy knows about:"
...
" Virtual register table: a table that allows to do STO and RCL in 100 different
virtual registers. Entries in this table are explained in one direction only,
since there are no references to registers in the ROM."

Does anyone know what functionality this table supports? I've never seen this referred to before, and I haven't been able to find any references to it in the usual Saturn/SysRPL documentation sources.

It reminds me of all the references to TopicVar and TOLVar that are listed as "38/39/49" entries in the extable, but aren't documented anywhere that I've seen.

Does anyone know anything about these entries?