HP41C ROM Addresses

[rprosperi]

Each page is 4K or 4096 bytes, (000 - FFF). The first 'digit' of a ROM address is the Page (0-F) and keep in mind that ROM words* are only 10-bits. The extra banks came well after the CPU design was fixed, via other hardware on the CX board or in the module (e.g. Advantage ROM, HEPAX or ZENROM or MLDL, etc.) and so are somewhat invisible to the CPU addressing.

Other gurus that really know what they're talking about can expand on this and probably explain it better, but this should be enough to get you pointed in the right direction.

* Corrected, originally had addresses - doh! Thanks Monte!