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HP-27S 50th Anniversary Limited Edition really?
10-23-2021, 03:53 PM
Post: #11
RE: HP-27S 50th Anniversary Limited Edition really?
(10-23-2021 03:39 PM)Mick_Go Wrote:  
(10-23-2021 03:11 PM)Allen Wrote:  This is an interesting find!

Maybe some things to consider when evaluating whether this is a prototype:

  1. The color of the badge is different, decreasing the likelihood of a face/plate swap
  2. Check the 4 posts in the battery compartment for any signs the calculator had been opened post-manufacture
  3. Check around the edges for any evidence the case front was pried apart (or bent faceplate)
  4. Check to see if the ROM ID is consistent with others made in the same time frame.
  5. Check the Serial Number (eg. 9999.. would suggest prototype)
  6. Check the provenance of the owner. The closer the seller lived to Corvallis, OR, the more likely an unusual item is legitimately rare/original.

Any evidence that the case was opened might suggest part swapping and not a prototype. I've seen several auctions over the years that claimed to be "rare prototypes" but upon evaluation (self test, ROM ID, repair evidence, keyboard label layout, etc..) nearly all were actually some home repair to save an expensive calculator rather than a rare prototype.

Evaluating based on information so far:

(True = Likely prototype, False= Likely not prototype)
  1. True
  4. Assumed True ( I don't know the production dates of ROM A)
  5. False

Nice find!!
The 4 posts in the batteries compartment are original intact
Nothing on the case is damaged or any sign of openning tentative.
I got it from eBay auction in Nevada
The serial # begin with 2749A0 and the four last numbers are all different.
For the ROM ID, I found this SPD1080272 in the test mode but I don't know if it's the right thing but compared to the SPD 1046864 from my 17B calculator the structure seems to be the same.

Here the eBay auction title and description for this calculator:

"HP 27S Scientific Calculator 50th Anniversary Edition"

"Special Edition HP 27S. Works like new. Includes case and original owners manual. Near perfect condition with one small scratch."

And five clear pictures of the calculator and its manual.
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RE: HP-27S 50th Anniversary Limited Edition really? - Mick_Go - 10-23-2021 03:53 PM

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