Specs are in the images. Probably only for a real cheese grader Mac geek, otherwise you just won’t understand the nostalgic value of these machines and the potential they still have for custom upgrades. 2 of these are running fine as of today. 1 of them ran fine couple years ago but hasn't been powered up until I tried today and it didn't boot. Probably just a minor issue and could be diagnosed and fixed if you know these machines. The fourth machine I have no clue what it does. Never turned it on or got around to looking at whats inside. Its in good shape and with a bit of tinkering I'm sure it would fire up also.