chessoclock
chessoclock is a simple chess clock running on a virtual terminal
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Merging chessoclock and a Minix 2.0.4 root disk gives us chessoflop.
Use chessoflop to turn your twenty years old 80286 into a chess clock without installing anything. Reverse the image on a floppy, put that disk on your old computer, turn it on and that’s all!
chessoflop image is available in the download page (it's the one all capitalized).