This is amazing; it’s an article from Programmable Logic DesignLine that describes how you can repair an old gaming system by using programmable logic (in the form of a Xilinx CPLD) to emulate
a hard-to-replacean obsolete (actually 35 cents each as Kyoorius points out in the comments, but assumed obsolete “for the sake of this project”) chip. The author, In Choi, has a great justification for doing this project:
You may be wondering why I did this exercise. Wouldn’t it have been easier to buy a video game console from this or even the last decade? I didn’t do the design simply to restore the video game – I did it for a number of reasons.
First off, I think logic design is fun (and I’m lucky enough to get paid to do it). Second, I wanted to show that I could create the RLD [retro logic device] to directly replace a failed part. But my main reason for doing the project was to create a methodology with an FPGA to show that there are indeed practical ways to overcome chip obsolescence.
(Pictured above, a screenshot from the cross-platform ParaJVE Vectrex emulator)