The bubble LED displays on the emulator board are much the same as the original, except they have an extra digit. (I didn't know the originals had 3 x 5 digit modules at the time, so mine has 4 x 4 digit modules. These HP displays were really cheap (about 0.70c per digit), but sadly they are no longer produced so some scrounging will be required. The PCB and PIC code can also drive a 2 x 16 LCD display but doesn't quite look the part. I was looking around for a red OLED display of similar dimensions but couldn't find anything and they don't seem to be cheap. cheers Tony On Sat, Sep 17, 2016 at 8:47 AM, Neil wrote: > I recently learned to use Autodesk Inventor (for high-school robotics > mentoring I do), and was thinking a 3D-printed OEM-looking case would > make a nice project, even if the displays are different. I'll make the > time to read through this over the weekend. > > Cheers, > -Neil. > > > > On 9/16/2016 6:22 PM, Anthony Nixon wrote: >> > Wow, this is great. Is the PCB sized to fit an original case? >> >> No, that would be a large undertaking, but I know someone who is >> trying to come up with a drop in replacement cpu board. The >> display/keyboard pcb is separate and big problem is that the original >> LED drivers are somewhat complicated with inductors directly dumping >> charge into each led segment and a fairly complex sequence of events >> to make it work. >> >> cheers >> >> Tony >> >> >> On Fri, Sep 16, 2016 at 11:43 PM, Neil wrote: >>> Wow, this is great. Is the PCB sized to fit an original case? >>> >>> Cheers, >>> -Neil. >>> >>> >>> >>> On 9/16/2016 5:33 AM, Anthony Nixon wrote: >>>> Hi all, >>>> >>>> Not sure if anyone is interested but I published the source code for >>>> the calculator emulator for the PIC16F1519 chip. >>>> >>>> It has the code to emulate the following HP calculators from the 70's = era. >>>> >>>> HP21, HP22, HP25, HP27, HP29C, HP31E, HP32E, HP33E, HP37E, HP35, HP45, >>>> HP55, HP65, HP67, HP70, HP80 >>>> >>>> www.teenix.org >>>> >>>> cheers >>>> >>>> Tony >>> -- >>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .