HP-41CX w/ XF-Module - just curious

[Ángel Martin]

(07-26-2019 01:09 PM)Sylvain Cote Wrote:  Then how do you explain the internal time module at page 5 case:

1. OFF
2. remove all the plug-in modules
3. ON
4. PRGM
5. XEQ "RCLALM" (CX TIME function)
6. OFF
7. insert TIME plug-in module
8. ON
9. PRGM
10. XROM 26,34 (CX TIME function not understood by TIME plug-in module)
    

The time module is a tad more complicated than the XF or others, because the page address is hard-wired. This means that both the internal CX Time and another TIME module plugged into the CX will both be configured "simultaneously" so to speak, regardless of the physical address used by that external TIME module..

It's only when you try to execute it (either manually or in a running program) then the OS kicks in, via the [GTRMAD] or [ARSCH] routines depending on the cases). Somehow the external one prevails over the built-in counterpart...

BTW this may also be taken advantage of by the CL, which comes with the Time ROM loaded but there's no TIME circuitry: when you plug an external physical TIME module to it that's the one that gets the deal, so to speak. Not sure it's the same mechanism but it'd make sense...

ÁM