As it looks like I am not going to be able to repair the monitor board for my VAXmate I am wondering if I can do anything with the outputs from the I/O board to drive an external monitor instead.
The connector to the monitor board has RGB+Intensity outputs at TTL levels. The horizontal sync has a frequency of 26.6KHz, active low with the high voltage 3.7V, Vertical sync is 60Hz. I don't believe that corresponds to any known standard, does it? I had a go at building this http://www.dasarodesigns.com/wp-content/uploads/2014/03/pet-composite-video- adapter.jpg feeding its output to a composite to VGA device to see if it would convert it to VGA, but no luck. Any ideas? Thanks Rob
