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modern operating system running on a Reagan era computer
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This is a most excellent place for technology news and articles.
You can run FreeDOS on an 8088 using the 16-bit version. Not exactly "modern", but still a recent OS.
Wild, I always thought it stopped at 286. Didn't realize it could go that old.
You got two options for that:
Official FreeDOS kernel: http://kernel.fdos.org/
And SvarDOS: http://svardos.org/