Posts: 128

Threads: 25

Joined: Jan 1970

Quad memory module is useless for an 41CX/CV. It's for an 41C and adds 4 x 63 storage registers; same as four "normal" memory modules 82106A, but uses only one slot.

Math module adds some enhanced mathematical routines to your 41C/CV/CX. I have one and can give you a list of the routines if you are interested.

Regards, Juergen

Posts: 1,755

Threads: 112

Joined: Jan 2005

The quad memory module does *not* work with an HP-41CX so there's no use at all in plugging it in, at worst you could lock the machine.

As for the math rom, you can use it with your 41CX if you've got one, but you'd be better advised to try and get the Advantage ROM instead, as it is far more powerful and convenient (for instance: extensive matrix functions, numerical solve, numerical integrate all implemented as machine-language keywords, instead of user-code RPN programs, thus 10+ times faster and no user resources required; plus basic financial functions, complex-number handling, vector computations, differential equations, etc).

Best regards from V.