While VR headset like the HTC Vive require a beefy computer and a lot of expensive equipment, all you really need to enjoy the pleasures of pure immersion are a battle-worn Commodore 64 and a 10 dollar pair of VR goggles.
Case in point, the VR64 is a DIY virtual reality system with the vintage hardware enthusiast in mind. The hack was created by 64jim64, a madman who decided to hook up a headset to his childhood home computer, a Commodore 64, which first went into production, oh, 35 years ago.
As he demonstrates in the above video, the VR64 is fully capable of playing VR games on this relic.
Speaking of games, so far there's only one game for this thing. It's called Street Defender and fits on a single 5 1/4th floppy. 64jim64 had to make the game himself, seeing how there's never been any reason for Commodore 64 VR games to exist previously. Considering it was only his third stab at game development, the game doesn't look too shabby. It's kind of a horde mode, with the player defending their position from an ever-advancing mob of insect-like ninjas.
Impressively, when you play the game with VR goggles, the ninjas actually appear to come towards you, according to 64jim64's blog post. The VR64 presents chunky pixels in legitimate stereoscopic 3D, creating an illusion of depth. 64jim64 achieved this effect by creating a program that splits the game into two images, one for each eye, then slightly tweaking each image until a field of depth was accomplished.
The actual construction of the device was less complicated, if somewhat tedious. Basically he bought one of those low-rent pair of VR goggles made for slotting your phone into and modified it. After notching out room for a 5 inch display and outputting the video signal to it, the project was pretty much ready.
If you want to build your own VR64, by all means, have at it. It's a pretty straightforward DIY project, with everything you need listed here. The most difficult part would be tracking down a working Commodore 64.