Here’s a video, with sound provided by AM radio, of a couple of classic demos running on a PDP-7 (at SDF probably)
Edit: also found (via HN) in the Internet Archive’s Wayback Machine here on their archive of the LCM channel on YouTube.
Two display hacks run on PDP-7 serial number 129 with the Type 340 XY display option. The 340 has a P7 phosphor has a slow decay which gives Munching Squares an eerie afterglow. Both programs read the left switches to modify patterns. A small AM radio was used to pick up RFI from the Type 347 controller. For the MIT AI lab hackers the Munching Squares “music” was referred to as Munching Tunes.
Apparently the Type 340 display has a P7 phosphor - I’m supposing the decay effect is much like the Type 30 display, as discussed recently
How does Spacewar! compare visually, real vs emulated screen?
Also previously
Spacewar! is 60 Today
and
LIFE - 4 Gosper Glider Guns on PDP-7 Type 340 display
(Unfortunately similar videos previously seen on YouTube are no longer available. Some might be found on the Wayback Machine.)
Here’s a photo of the Type 340, as posted to the below-linked discussion, with the text “Courtesy of SDF Vintage Systems”
See also the gist P7 CRT phosphor resources with lots of links
via Stephen Jones on the PiDP-10 mail list.