carlsson wrote:
Oh yes, hardware extentions of various kinds. Hard drives, memory expansions, CPU upgrades, networking, external keyboards, possibly even video and sound upgrades. But it would require the OP to own or buy one of these old computers to begin with, and then immediately get the upgrades he wants. Not quite the same thing as buying a new (old) computer that is preconfigured as he wish. Maybe something along the line XGameStation, C-1 and all other reconfigurable hobbyist projects would be interesting as well. They are not vintage in terms of age, but at least "off-topic related" in terms of capacity and heritage.
Or you can build a whole new Jupiter Ace from Scratch (using Schematics from enthusiasts websites), and then proceed to looking into getting a Jump drive working on it! :-D