Hi, all.
A few days ago I bought a DEL. SERV 1 module (USPS) announced at the local e-Bay (Mercado Livre). I had the ROM images downloaded from T.O.S. - which states it is undocumented - and inspected its contents. I found interesting the fact that, amongst its set of user-coded programs, it has five X-Functions:
XROM 21,21 CLFLThese are enough to create some data files, clear their contents, store and retrieve data on them, control the pointer for each of them BUT it does not provide a PURFL (?). I was wondering that it could also have some X-memory inside of it, but it would be too much to ask for...
XROM 21,22 CRFLD
XROM 21,23 GETX
XROM 21,24 SAVEX
XROM 21,25 SEEKPTA
(edited to corret these XROM numbers)
I grabbed it today and interestingly I saw a [WORKING] message being briefly displayed when I first turned the calculator ON after plugging the module in, but I did not check if some of the memory registers 'disappeared' (as for creating some memory bank). Anyway, the first thing I did was to try CRFLD with '10.0000' in X-register and [TST] in ALPHA. I got a (somehow expected)
NO X-MEMORYin the display after the CRFLD. But then I thought: 'I need an X-Functions module for the first 124 X-registers so I can access the ones in the additional X-Memories; but this module provides these standard X-Functions, which leads to the conclusion that the functions in the X-Function module itself would not be needed if this module is plugged in... Why not?'
Yep, I plugged an X-Memory into the same HP41CV and it worked with these five X-Functions in the DEL. SERV 1 module: I could create data files and manage data with them. I did not try it yet, but I see no reason for these functions to work the same if the DEL. SERV 1 is plugged in as a ROM image.
I can only conclude that these five functions are not the same ones from the X-Functions module, instead that they are re-written versions of the original X-Functions with a different memory address mapping.
SO... it means that the functions in the X-Functions ROM image might also be changed in order to run in new gadgets like Meindert's MLDL2000 or Diego's NoV-series, CLONIX included, and access the RAM in the X-Memory modules directly, skipping the first X-Functions native 126 registers.
The 41CL itself already has all X-Functions and X-Memory facilities, so it does not apply.
Is there anything wrong with my reasoning?
I do not have knowledge enough to to do this right now, but I'm teasing myself to compare these five functions to the original ones in the X-Functions module. I'll need to read some books in order to reactivate some already-forgotten knowledge about M-Code and to add extra ones I do not have about the X-Memory access.
But I'd like to hear something from you guys; chances are I am just a happy boy scout finding my first (fake) rare coin... believing it is so.
Cheers.
Luiz (Brazil)
Edited: 8 Nov 2012, 8:49 a.m.