HP-41C and HP-41CX

[Jeff D]

I have purchased and am in the assembly process of a MLDL2000, Thank you Meindert. I have noticed that with the HP-41CX Halfnut and Fullnut I get intermittent results when using the MLDL2000. Ususally the HP-41CX will, when a CAT 2 is done, drop into neverland when it gets to the M2K ROM and then the display goes blank for a while and then returns to finish the CAT 2.Usually the listing in the CAT 2 is gibberish when trying to display the M2K ROM. Now with the HP-41C Halfnut tall key version, everything runs awesome with the MLDL2000 connected. Run a CAT 2 and everything is good. Is there a difference with the way the CX versions connect with modules vs the C? I am confident this is not an MLDL2000 problem because it works on the 41C. Is the "zebra" connector slightly thinner or different from the CX? Is the case tighter on the C vs the CX?
Has anyone had a similar problem before?
Thanks,
Jeff

[Raymond Del Tondo]

Hello,

there are various differences between the C and the CX.

The Catalog function of the CX has been slightly changed,

so CAT 2 will display module headers only by default.

This way the user can get an overview of the installed ROMs,

and only view the details of the wanted ROM.

Please also check the CX manual about this feature.

I didn't check the M2K ROM in particular,

but defective Catalog displays are usually

an indicator of either a bad FAT,

or a special character in a function name.

The M2K ROM intercepts key sequences at specific occasions,

but Meindert should be able to tell you more about it;-)

About the zebra connectors:

There were different fashions of these connectors,

I know of at least three completely different constructions.

The pink rubber type ones may cause problems over time because they will shrink,

and the metall ring type connectors are sensible against corrosion.

Note that the CX halfnut doesn't have these connectors,

since the hardware layout is completely different to the non-halfnut calcs.

HTH

Raymond