Sorry, the clipper card wasn't added in 82 it was added in 81. It was modified to add AO Driver in 82. I'm guessing the Clipper board and controls were added as part of the Crystal Odyssey Mods. The Clipper did what it's name implied. It gave the Laserist control over where the positive and negative ends of the X & Y signals (from the master gain control of the CYGN-A) were clipped. The two clipper circuits used one each of the AD811 and AD821 dual transistors so a it would take a bit of a redesign today. FWIW I never liked the clipper effect on the G-124 open loop scanners, and I never saw anything cool enough to make me really want to use it. I'll try to make it by UPS this weekend and send the packages sitting on my steps.
"There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso