That's kind of it though, the lines being drawn one at a time, in real time, you just can't emulate that. You would need refresh rates in the thousands of hz to make it look even close to right, and that completely ignores the persistence of vision effect.

Believe me, I tried. I explored damn near every possibility on 6 months of salary, it boiled down to an FPGA clone hooked up to a custom CRT driver and that still had issues with how it would look because the Vectrex uses an unhinged aspect ratio. If your tube isn't the right shape all of the graphics get messed up because the system draws on a polar plane. It's a fucking mess, I really wish people would stop trying to emulate it and just put the cash into making a proper tube. Would save actual engineers a lot of headache.