The HP67 microcode emulator and all associated interfaces, documentation and designs are copyright 2015 Sydneysmith.com.
This work is based on a physical calculator created by Hewlett Packard. All credit for the original idea, the choice of functions and the layout goes to HP.
This software builds on the work of a number of people:
Dave Cochran who did the original microcode for the original calculator (HP35) and which evolved into that for the physical HP67 and for this emulator.
Neil Fraser who showed me many years ago that you can write a workable calculator in javascript.
Eric Smith who reverse engineered, and wrote Nonpareil – an emulator for, the classic HP calculators.
David G Hicks who ported it to java.
Peter Monta who did some amazing things to read the ROMs in the original hardware.
Jacques Laporte who created the original HP67 card reader emulator. (Much of Jacques site is now available here.)
Ashley Feniello who showed me that javascript is now fast enough to emulate old processors with his HP35 microcode emulator.
Francois Roulet who showed me that this was possible even with more complex calculators like the HP65.
None of these people endorse the emulators on this site and they are not responsible for any errors or omissions in the emulators on this site.
(It was my intent to simply use the HP65 emulator I’d modified from Francois’ and plug in the HP67 ROMs. That was the point I discovered that, whilst the ’65 and ’67 are clearly related and the only obvious difference on the outside is the color scheme, there are a LOT of differences inside.
I really came to understand the difference then between the classic calculators and the woodstock models. What was to be a five minute task became a month long activity and a complete rewrite of the internals as guided by Eric’s, David’s and Jacques’ similar work in C/Java. It’s not a straight port of theirs – as there are a number of differences – but their work clearly contributed.)
