Perfect Companion for your 7L12... 7623A storage mainframe
 

Tektronix 7623A 3-hole storage mainframe.
Bistable and Variable Persistence modes.
Works great
Perfect for slow sweeps on a 7L12 or 7S12 or single shot.
Came in handy testing a spot welder.
no plugins.
pictures of unit and stored trace here
http://nm7u.tripod.com/homepage/te.html
$75 pick up in Tigard, Oregon
Too heavy to ship
maybe trade for something
mike