Hardware Archeology: HP 48GX

Back in college, programmable calculators were starting to become a thing and by the time I hit grad school, the HP 48GX came out. It was the closest thing to a handheld computer that I’d ever had.

For the time, it was truly impressive. It could do all the standard calculator functions but it could also run simple programs and I wrote a few.

One in particular that I was pretty proud of was an implementation of a card game called Set. It’s based on trying to find sets of 3 cards that are all the same or all different in 4 categories: number, color, shape, and pattern. But the HP 48GX, as advanced as it was, was only black and white and had very low resolution (131×64 pixels). So I simplified the shapes and instead of colors, I re-used the pattern in the background of the shapes.

It worked out pretty well. The funny thing was that the processor on the calculator was so slow that I couldn’t check all the possible combinations very quickly. Instead it just checked for one combination per loop and it was possible for a human player to actually find a set before the calculator.

I managed to dig up my old calculator and was amazed to find it still worked when I put in some fresh batteries. Unfortunately, the memory was wiped but I found an archive of my old HP 48GX work and still have the original program and readme.txt file.

Leave a Reply