An attempt to standarize HP-41 Bank Switching.

[MeindertKuipers]

It is really good to have some kind of standardization. I recall that there was a table published in another thread (cannot find it now) with all variations of BS implementations.
This may be important for the DM41X and MLDL2000 platforms. I am a bit hesitant to change the implementation in the MLDL2000 (port based BS in ALL pages, including 0-7). Will do some testing with LIB4 in the lower pages in the MLDL2000.