Every 80s calculator that I used used the batteries that are still commonly available, CR2032 mostly, but some CR2025 and such as well. The hard to find batter

Every 80s calculator that I used used the batteries that are still commonly available, CR2032 mostly, but some CR2025 and such as well. The hard to find batteries (not impossible) tend to be the wierd voltage batteries that cameras mostly used for light metering.