HP · RPN programmable · July 1979 to January 1985
HP's code name for it was Coconut, and when it arrived in July 1979 it was the first calculator of its kind with an alphanumeric display: programs could prompt you in words. Its four ports on the top edge turned it into a small system. You could add memory, application pacs, a card reader, a printer, a wand that read barcodes, and later the HP-IL loop for cassette drives and more. BYTE called it the most versatile machine ever in 1980. HP-41Cs flew on early Space Shuttle missions, and one that flew on nine of them is in the Smithsonian. The base 41C has 63 registers of memory, so most owners filled ports with memory modules until HP built that memory into the 41CV.
Good forEngineeringCollecting
Bench check
Should come with it
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
The plug-in modules we cover for the HP-41C. Each page says what it adds, what’s already built in and how to check one.
HP
Module$35–$45 typical ask
HP
Module$30–$65 typical ask
HP
Module$140–$190 typical ask
HP
Module$80–$120 typical ask
HP
ModuleSpecs and what to check →
Leaked batteries are the big one, because corrosion spreads into the flexible circuit behind the ports and keyboard. Poor contacts cause lockups and lost memory. A card reader in the listing is a separate 82104A, so check it on its own.
New to old calculators? The condition checklist covers battery corrosion, displays, keys and card readers, and RPN in one hour gets you typing on an HP.
Buying guide
We'd buy allthingsimportant's 41C titled tested, with two memory modules and batteries, at $206 delivered, the bottom of the $200-400 band. The modules matter, since a bare 41C has only 63 registers, which is why HP built that memory into the 41CV in 1980. Of at least 23 for sale, a bare calculator with its case starts at $76 delivered on a no-bid auction that will climb, while bundles with modules, a card reader or manuals ask $206 to $386. Leaked batteries are the big killer on a 41, because the corrosion spreads into the flexible circuit behind the keyboard and ports, so ask for a photo with the battery holder out and ask whether it keeps a stored number through a switch-off. Skip the $695 card reader bundle at 2.5 times the $275 median, and the zero-feedback seller in Cyprus charging $50 for shipping.
$76.48est. delivered
The lowest price on a 41C titled tested and working, a no-bid auction at $76 delivered with its case, so expect it to climb. It has no modules, so you get the base 63 registers, and the 2139S serial in the title dates it to 1981, built in Singapore.
Vtg HP- 41C Hewlett Packard Calculator Tested/Working w/ Case Serial 2139S11945
$206.00est. delivered
Titled tested, with two memory modules and batteries, at $206 delivered from a 100% seller. The photo shows the calculator alone, so ask to see the modules and the battery bay.
HP 41C Calculator with 2 Memory Modules Batteries Tested Made in USA
$206.00est. delivered
Shipping is quoted, it comes with batteries, and the extra memory gives a 41C room for real programs. No case is named, so budget for one if you'll carry it.
HP 41C Calculator with 2 Memory Modules Batteries Tested Made in USA
$91.69est. delivered
Sold as is with its case at $92 delivered, more than $100 under the band. Pay parts money unless a photo of the open battery bay comes back clean, since leaked batteries are what usually kill a 41.
1979-1990 Vintage HP-41C Hewlett Packard CALCULATOR w/ Case As Is
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$76.48est. delivered
$64.99 + $11.49 shipping
Auction · no bids yet · ends in 4d 9h
Good buy
Titled tested and working, with case. Auction with no bids, so it will climb.
Seller: paumul_4174
100% positive
Used$206.00est. delivered
$195.00 + $11.00 shipping
Buy It Now$195.00
Good buy
Titled tested, with two memory modules and batteries. No case named.
Seller: allthingsimportant
100% positive
For parts$91.69est. delivered
$79.99 + $11.70 shipping
Buy It Now$79.99
Project piece
Sold as is, with case. Ask for a photo of the battery bay.
Seller: mrscoolhandchuch
99.5% positive
Used$112.10est. delivered
$100.00 + $12.10 shipping
Auction · no bids yet · ends in 4d 14h
Our take
With Quad Memory and Math 1 modules, serial from 1980, USA. No test claim, and the no-bid auction will climb.
Seller: mose7
100% positive
Used$289.85est. delivered
$275.00 + $14.85 shipping
Buy It Now$275.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Titled works great, with four modules and case. Overlays and reference cards in the photo.
Seller: sellit826
100% positive
Used$386.03est. delivered
$380.00 + $6.03 shipping
Buy It Now$380.00
Our take
Titled with case, overlays, the original box and a working card reader.
Seller: jim123e
100% positive
Used$200.00est. delivered
$150.00 + $50.00 shipping
Buy It Now$150.00
Check the seller
Three memory modules. Zero-feedback seller in Cyprus, with $50 shipping.
Seller: lysche_3126
No feedback yet
Used$695.00delivered
$695.00 · free shipping
Buy It Now$695.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Priced high
Card reader, manuals and box in the photo. About 2.5 times the median.
Seller: vfscientific
99.9% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 15, 2026.
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