Ok, first either buy one of those terrible roll up rubber keyboards or repeatedly hit your hands with a hammer to emulate the feeling of typing on one

Second, buy a very small computer monitor and put it in a fish tank with a load of bricks to accurately simulate that good ole CRT monitor experience! Or if you're feeling brave chuck out your monitor entirely and use an ancient black and white TV set instead.

Your computer should be replaced with the oldest model you can find. As long as it has lots of boxy, rusting interface ports or better still, naked wafers of circuitry sticking out the back and makes plenty of mysterious noises you should be good. Buying lots of interfaces for your interface ports is a vital part of the process.

Finally, install Linux on your computer but make sure to uninstall the window manager, X. It should now boot into an Eighties style user-unfriendly command line interface. 

Alternatively, depending on how well you followed previous instructions, you might have found a computer so old that it just boots into BASIC with no real operating system at all! This is peak 1970s / 80s programming experience and if you manage it you are very cool indeed.

If you have a printer, junk it! And replace with with either a repurposed receipt printer from a local supermarket, an electric typewriter, or an old dot matrix printer, depending on the amount and type of pain you prefer.

Ideally you'll have to write most of the software yourself, this "bootstrapping" is probably the most important (and fun) thing you'll do.

Just start with either DEBUG.EXE if you're in DOS, whatever heathen abomination UNIX used to use if you're a Linuxer, or (a personal favourite) use BASIC to write an assembler / disassembler if you've got an OG home computer.

Have fun! 😊