Alternative HP-41CL mainframe (OS ROMs) update for beta test

[hth]

(10-01-2019 07:39 PM)Sylvain Cote Wrote:  ok, it seems to work.

[.. bugs ..]

Try without mixing NFL and new routines. After memory lost, perform MAPEN, then EMROOM. The first function that detects that extended memory has not been initialized will set it up. (If that fails, try the PPLUG commands again, I had one case where it managed to have a partial mapping between RAM and flash which caused weird problems.)

You will not be able to jump back and forth between the NFL code and the new one. The reason is that the NFL code makes lots of assumptions based on that there are up to two possible extended memory modules. It will just "know" certain invariants like if the module is not 2xx, then it can only be 3xx. While it is flexible in that that extended memory modules can be (physically) plugged in and out (which the new code does not support), it is not at all flexible with additional memory pages. Another issue is that the link registers between modules are 040, 201 and 301 in the NFL code. That is still true, but now it also adds in 400, 500 and so on. That a link register can be anything other than x01 outside the base module is nothing the NFL routines can handle. There are also assumptions about the top register of a module that is also invalid from page 4 and up. I did it this way to utilize every possible register, there are no gaps from page 4 and up.

I suspect the CCD ROM has copied the NFL routines and does not call the entry points in 41CX, which is probably to be expected as it wants to work with all 41 models, 41C/CV/CX.