HP Forums

Full Version: What age is this 35
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

I have long thought production of the hp35 started in 1972 but after reading the established method of deciphering the serial number I got the 43 week of 1971 made in America out of this No. 1143A42805 I feel sure some one out there will put me straight. Would be pleased to hear from anyone who can help. Ps if I've missed something obvious here, be kind. Scotty.


I think they produced them before they sold them;-)
So if they were in stores in 1972 production may have begun in late 1971.



There's a guide to decoding serial numbers and a list of early ones at:


Thanks fellers for your response to my 35 age. Jim I previosly check the guide you menioned, that's what bought me to the original question. This calculator was purchased from a retired hp rep living in Australia. His experiences in the company had many contacts with both Bill Hewlett and Dave Packard many photographs were shown to me which included himself with Bill and Dave. What I'm trying to point out this is very authentic calculator.The gentleman concerned told me hp felt only 10000 35s were expected to sell before before the market would be flooded. This is what puzzles me this claculator was given as a gift for sales preformance from hp, it fits the description of a model 2. It is not a red dot model but was supplied with a interim recharger made by hp with a sticker saying not for sale.This is what I cant understand as the serial No. is 1143A42805 that gives the 43 week of 1971 with 42805 units made. As this appears to be a model 2 as 35 dose not appear on the front label, how many model 1 units were made 10000+? This makes 50000 odd calculators made in 1971 before sales started,maybe this was a normal way for gearing up for world sales back then. I suppose that make the story about only 10000 a bit of a myth. Hope I haven't board all to death, just thought someone would know the answer to this. Scotty.


I think the critical bit from that page is:

"The correspondence of serial numbers to dates is only approximate. In some cases, they may be better indicators of the date of manufacture of the case or label rather than the entire calculator. With some desktop models, it appears that the date code was changed only when there were manufacturing changes. On the other hand, different versions of the HP-35 can be found with the same date code. (The museum has examples of type 3 and 4 with date code 1346 and some of the type 4s have lower sequence numbers than the type 3s!) "

Lower down the page you'll see that the lowest seen S/Ns for both type 1 and 2 are 1143.