I have two brand-new 13" green screen monitors available. We got them at work from a surplus source a LONG time ago, I think to replace failing monitors in Graph-on 140 terminals. These are Motorola DS4003-500 units, with AC power supply for either 120 or 240 V operation. They take a card-edge connector for video and sync. (I think they are RS-170 for composite sync, but I'm not completely sure.) I used a scope to pick up the horizontal frequency, it was 53.6 us or ~ 16.5 KHz. I did power one of them up, and it gave a green raster when the brightness was turned up. Anybody interested? Jon