Using Quad memory w/ 41cx


Is the 41-c series quad memory module compatible (useable) with the 41cx?


No. The 41 family can only address one of those, and the 41CV and 41CX have it built in. They already have the maximum "normal user memory". Don't put the Memory or Quad Memory modules in a 41CV or 41CX, as they will not work correctly, and there is a small chance that the modules or the 41 could be damaged by bus contention.

The 41CX has the "Extended Functions Module" (XFM) built in as well; that contains 127 usable registers of Extended Memory. You can add one or two Extended Memory modules in the ports; each one adds 238 usable registers of Extended Memory. Note that there are some restrictions on the arrangement of the XMEM modules in the ports.

Extended memory is accessed by the Extended Functions, so it doesn't work in the same manner as normal user memory. It stores files, so you can think of it as being similar to a ramdisk. You can store programs or data in it, but you can't access it directly (except by complicated synthetic programming tricks).


Eric, thank you for your very thorough and very prompt response. I fully understand not to use this module on my 41-cx calculator. this site (and your response) is a great resource - thank you once again!

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