ASCIIMath creating images

Thursday, August 30, 2012

Panasonic HHC Schematics by Tony Duell

(TL;DR version: the scans are here)

Some years ago, I picked up a Panasonic HHC, having had an interest in the small hand-held BASIC computers for a while.  As it turns out, the HHC does not use basic at all, and is by default not really "open" in any way - there was a BASIC ROM available, but generally the thing was used as a specialized calculator with custom ROMs.  Still, It's a cute little machine with the interesting feature of using a 6502 inside, and it came with a printer that uses regular paper, and even the internal batteries still work.

Recently, there was a discussion about it on the Classiccmp mailing list, and Tony Duell - known for his classic computer electronics acumen if not his take-no-prisoners approach to typing emails - mentioned that he had traced out the circuits of this little machine.  This got me (and several others) interested, and he offered to make these available to the general public if someone would scan them and place them somewhere on the web.  The physical pieces of paper from Tony were scanned by Dave Colver, who in turn sent me the images.  I did a bit of cleaning up (nothing more than adjusting levels to remove some JPG compression artifacts) and collated them into a PDF document and you can download them from here: Panasonic HHC RL-H1400 Schematics.

Unfortunately, my HHC is at this moment a couple of thousand kilometers away, in a box at a friend's house in Pointe-Claire, Canada.  However, once I live in a place where I have a workshop again, I will mess around with it, for sure.  Dumping the ROMs would be a good start!