A long time ago, in a galaxy far far away, when the ZX Spectrum was in its heyday, a game based upon the very first Discworld book, The Colour of Magic was released upon the rubber-keyed doorstop.
If you've got a suitable Speccy Emulator you can sample
this colour clash classic for yourself - it's available in snapshot
format, in the Pratchett Archives, along with a solution to
help you out in case you get stuck. You can probably find better
spectrum emulators by searching the net, but you need one that can
handle emulating loading games from 'tape' so bear that in mind.
Despite its 'scr' extension, The Colour Of Magic is not a screensaver.
You have to load the .scr file into a Spectrum emulator.
Download a Spectrum emulator to play the game on.
Take a look at the full solution to the game.
Follow the instructions with your emulator, and relive those poor-quality keyboard days. Three cheers for emulating an ancient computer on a thousand pound PC.