HP · 82180A
HP's 82180A arrived in late 1981 with the functions HP-41 owners had been asking for: assigning keys and resizing memory from inside a program, moving blocks of registers, working with strings of letters, and keeping files of programs and data in a separate extended memory with a text editor. HP printed X FUNCTIONS on the module, and that's what everyone calls it. Its own 127 registers can be stretched to 603 with up to two 82181A X Memory modules. The 41CX of 1983 has all of it built in, so this is a module for the 41C and 41CV. v1 of this site listed an Extended Functions module as a separate product. There was only ever this one.
Module check
Should come with it
Contacts are the main risk, as on any 41 module. HP's own addendum lists a couple of known bugs with VERIFY and PURFL, which are quirks of the ROM, not faults.
Choosing modules for a 41? The HP-41C, CV and CX explainer covers memory, ports and what each model has built in.
Buying guide
With only three X Functions modules for sale, the $80-120 band isn't a market read, so judge each one on what's included. We'd buy jtomaha's at $76 delivered, the cheapest, or pay $142 delivered for epod_egur's package from Canada with the owner's manual and the Extended Functions Made Easy book in the photo. It's for the 41C and 41CV, since the 41CX has these functions and the extended memory built in, and it's the module an 82181A X Memory needs before it will work. None is titled tested, so ask the seller to run EMDIR with it plugged in, which should show a directory even if it's empty, and ask for a close photo of the contacts.
$75.87est. delivered
The lowest price at $76 delivered from a 100% seller, with the X FUNCTIONS label in the photo. It's the module alone with no test claim, so ask for EMDIR run on a 41C or 41CV.
HP-41 Calculator X FUNCTIONS Module - Hewlett Packard 5061-5256 82180A CV CX C
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$75.87est. delivered
$69.95 + $5.92 shipping
Buy It Now$69.95
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Good buy
Module only as titled, shown on a manual page, so ask whether the manual comes. No test claim.
Seller: jtomaha
100% positive
Used$84.99delivered
$84.99 · free shipping
Buy It Now$84.99
Our take
Module only, X FUNCTIONS label in the photo. No test claim.
Seller: tech_revived
99.9% positive
Used$141.72est. delivered
$105.35 + $36.37 shipping
Buy It Now$105.35
Our take
Module, owner's manual, Made Easy book and reference card in the photo. Ships from Canada.
Seller: epod_egur
100% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 15, 2026.
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