DEC PDP-7 w/ Type 340 display running Munching Squares and Spirograph

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.