Alternative Monitor for VAXmate

[Rob Jarratt]

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