2018-01-21

Recovering passwords from a Casio graphing calculator

I bought this Casio CFX-9800G calculator in 1995. It's been through everything with me, even, apparently, my college electronics courses (per the "ELEC 120 Progs" thing I found on it):


I bought it because it was about 2/3 the price of the competing TI-81 calculator that was "required" for whatever math class I'd found myself sucked into that semester (I think statistics) and because it was the first calculator I'd ever seen with a color display, even if it was only 3 colors (Orange, green and blue). My math teachers hated anything that wasn't Texas Instruments, because they'd received formal training and supplies from TI. Of course, this extra annoyance was a bit of a pride point for me, and the one kid with his HP 48G.

Now, it sits on my desk at home for calculations that exceed the easy capacity of bc(1) and xcalc. Poking through the program menu, I ran into a few games and helper scripts I've written over the years. Some were password-protected.

It was about this time that I recalled buying the data cable and software. Somehow, I still had the CD on a spindle of old commercial software (among gems like Need For Speed SE, MechWarrior II, and CheckPoint Firewall-1 4.0) and my cable stash is organized enough that it was easy to find in the bucket labeled "Strange proprietary serial cables". One problem: Windows 10 doesn't like 25 year old Casio software. Rebooting my OpenBSD netbook into Windows 7 Starter Edition (ugh) did the trick, though. Add a USB/Serial dongle, and we're off!

I connect the cable, put the Casio software into "receive" mode, then do a data dump from the calculator itself. Things are looking up! Unfortunately, I can only see that these programs exist on the calculator, I can't do much with them aside from delete them from the archive.


I open the file in Notepad++ for giggles, and I'm pleasantly surprised. This whole catalog is ASCII. And I also found a password I haven't used since the late 90s.

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