Downloading...
MicaSOFT Electronics & Microelectronics Tutor
Here's an interesting DOS program from 1992. This is the last of four programs from MicaSOFT that cover basic electronics and computing - starting with the atom and ending with a section on software.
The first three programs are quite buggy but this is the most interesting one. Unfortunately a couple of the topics in this one are broken and will crash on certain pages.

As well as the lovely diagrams and animations, there are some fun historical oddities: I can't find any information about MicaSOFT, but according to an advert in PC Mag, these tutors originally cost $199 for a single user, and came on four 5.25" disks (or if you preferred, two 3.5" diskettes).

The program is running inside an Emscripten port of DOSBox.