MiSTer project that is installed on the DE10-Nano board can only output video using the on-board HDMI connector. However if you want to get the real retro gaming experience then you can attach the MiSTer IO Board. Among other things, this add-on board let's you output 15KHz analog RGB video and audio signals that will let you connect to a CRT monitor. This blog post describes how to build such a board.
A while back I have assembled this bench power supply kit, which I received as a gift from my friend Eric. The kit was published in a Dutch electronics forum (Circuits online) as PCB Lab voeding. It was time to create a casing for it as it was just lying around in my drawer and was not really being used.