Actualy the Pentranic, Makvision story is much more twisted than that.... I won't get into details... I once consulted for pentranic and worked for Makvision.
In both cases the owners ran them to the ground financialy. Pentranic went broke and Makvision....
That is why 2 years ago I reched the conclusion "If you want something done right- do it yourself" and founded Nieman Video Displays.
You won't get technical support from Makvision.
I use some of the same suppliers Makvision used to. From what I heard they no longer manufacture their product and in fact may never even touch it, just resell.
If you go to my website Niemandisplays.com, go to our products, then CRT vased products select the standard res (CGA) the schematic you download there is what you need.
Good Luck
Rick Nieman
Rick@Niemandiplays.com
www,Niemandisplays.com