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Fun and Profit With Obsolete Computers
An anonymous reader writes "C|Net has a story about the value of aging computer hardware, and the subculture of people who collect them. The story details some of the more enthusiastic collectors currently participating in the hobby, as well as their old-school beautiful hardware. '[Sellam Ismail] recently brought a quarter century-old Xerox Star computer back to life to be used as evidence in a patent lawsuit. The pride of his collection is an Apple Lisa, one of the first computers (introduced in 1983) with a now standard graphical interface. Such items sell for more than $10,000. In an old barn in Northern California that also houses pigs, Bruce Damer, 45, keeps a collection that includes a Cray-1 supercomputer, a Xerox Alto (an early microcomputer introduced in 1973) and early Apple prototypes. '
In another 30 years, many of these oldies will have died (if they haven't already) due to a variety of reasons. Mostly plain mechanical parts (cheap plastic, foil keyboard switches, rubber rolls crumbling and so on). Also think of programmed parts (EPROMs, programmable microcontrollers included for a specific task etc) that go into an erased state after a long, but finite time (usually several decades).
But if your machine still works after 30 years, plugging it into a monitor won't be the hard part. Last time I checked, even many of the latest LCD TV's have a variety of analog inputs. Why? Because analog inputs are often useful to hook up monitors to the widest possible variety of replay equipment. Even if many modern equipment is 'digitised', you're a fool to think that the option to display analog signals will disappear completely. Think of analog signals in general as a lower-level thing than most digital signals, meaning it's easier to do something with it, and easy to include in display equipment at near-zero added cost.
With audio, things are even easier/simpler.
For example this Sinclair ZX81 produces a TV UHF signal, but it's easy to pick up a plain composite video signal from its insides. Some soldering of wires might be required, but I expect you'll have a hard time finding a brandnew LCD TV that is not capable of producing an image with that.
One thing I personally like about these early Sinclair machines, is that they're built simple enough to recreate them with plain discrete logic, and perhaps a few analog parts. No complex video circuitry, no audio, a well-understood CPU and so on. Enough for instance to program a FPGA to behave like a ZX81 (try Google if you're interested). Also makes these machines relatively easy to repair. For ZX81: if you got the time, tools and knowledge, you can repair/keep these machines running as long as you want. I myself own 2 of these, last time I checked both were still working. 25 years old by now, and I'm pretty sure I can have these in a working state longer than a PC bought new today.