from the there's-no-school-like-the-old-school dept.
Remoticon 2021 // Rob Weinstein Builds An HP-35 From The Patent Up:
Fifty years ago, Hewlett-Packard introduced the first handheld scientific calculator, the HP-35. It was quite the engineering feat, since equivalent machines of the day were bulky desktop affairs, if not rack-mounted. [Rob Weinstein] has long been a fan of HP calculators, and used an HP-41C for many years until it wore out. Since then he gradually developed a curiosity about these old calculators and what made them tick. The more he read, the more engrossed he became. [Rob] eventually decided to embark on a three year long reverse-engineer journey that culminated a recreation of the original design on a protoboard that operates exactly like the original from 1972 (although not quite pocket-sized). In this presentation he walks us through the history of the calculator design and his efforts in understanding and eventually replicating it using modern FPGAs.
He started with the original HP patent and began to build tinyFPGA models. One part of the patent was treated as a black box, but he was able to reverse engineer what it does based upon the parts that interacted with it. He made a brief video demonstrating his recreation side-by-side with an actual HP-35.
Rob Weinstein's Remoticon 2021 presentation can be found on YouTube.
As part of his reverse engineering efforts, Rob Weinstein got to see the clever approaches the HP engineers implemented.
Early LED devices were a drain on batteries, and HP engineers came up with a clever solution. In a complex orchestra of multiplexed switches, they steered current through inductors and LED segments, storing energy temporarily and eliminating the need for inefficient dropping resistors. But even more complicated is the serial processor architecture of the calculator. The first microprocessors were not available when HP started this design, so the entire processor was done at the gate level. Everything operates on 56-bit registers which are constantly circulating around in circular shift registers.
[...] This is an incredibly researched and thoroughly documented project. [Rob] has made the design open source and is sharing it on the project's GitLab repository. [Rob]'s slides for Remoticon are not only a great overview of the project, but have some good references included.
(Score: 0, Informative) by Anonymous Coward on Sunday April 17 2022, @04:40PM (8 children)
... and then Carly Fiorina came in and fucked everything up.
(Score: 0) by Anonymous Coward on Sunday April 17 2022, @05:23PM (4 children)
I paid a small fortune to buy a backup HP-32SII in case my primary one over kicks the can. Still in the original packaging.
(Score: 0) by Anonymous Coward on Sunday April 17 2022, @05:35PM (3 children)
You don't say how long ago...but even coin cells may leak after years of storage. If the batteries are installed it's a good idea to remove them.
(Score: 0) by Anonymous Coward on Sunday April 17 2022, @06:59PM
This goes for any rarely used battery powered device!
(Score: 0) by Anonymous Coward on Sunday April 17 2022, @11:12PM (1 child)
No batteries installed. Paid a fortune 10 years ago. I can't imagine what the prices are at now.
(Score: 0) by Anonymous Coward on Monday April 18 2022, @05:49AM
What was "fortune 10 years ago"??
Currently it looks like +/- $100 on eBay. Some rough ones, "Parts Only" for ~$50. A few that claim to pass self test and look clean in photos for ~$150.
(Score: 3, Insightful) by khallow on Sunday April 17 2022, @06:17PM (2 children)
It was a leadership failure in the HP board of directors. That in turn was probably driven by a bunch of Other Peoples' Money funds that had more interest in appearances (probably to pump HP stock) than in a successful business.
If they hadn't hired Fiorina, they would have hired someone else just as terrible.
(Score: 1, Insightful) by Anonymous Coward on Sunday April 17 2022, @11:15PM (1 child)
It's the ultimate fate of all tech companies. Once all the original founders who understand technology are gone, all you are left with business majors, who only understand the promotion of other business majors. None of them can ever truly understand the technology, which is why the are business majors and not Engineers.
Intel began this path back around 2001. They actually had to bring back a real engineer because at least someone at the board kind of understood their mistake. But it's too late. The indians have taken over all levels of middle management, and people from India do not understand Western ethics/values, so every project has middle management lying about progress and schedules, meaning upper management can't ever make correct decisions because all the data they are fed is bad.
(Score: 0) by Anonymous Coward on Tuesday April 19 2022, @03:05PM
Wait so non-Indian people from the USA don't lie about progress and schedules? You sure about that?