14 Jun
2016
14 Jun
'16
4:09 p.m.
On Tue, Jun 14, 2016, tony duell wrote:
Thanks to both of you. This might give me a goal to work toward while
learning electronics.
Is the 15kHz RGB signal fundamentally the same as the VGA signal, except
at a lower horizontal frequency? If not, how do they differ?
--
Eric Christopherson
I am in
possession of two Magnavox (North American Philips) CM8562
monitors. Out of the box they handle composite and digital RGBI (CGA)
input. What I'd like to do is get one to handle analog RGB (like arcade
boards, Amiga, Atari ST, and Apple IIGS put out). I wouldn't think this was
possible, but I seem to have a certain memory that I saw mention of doing
My guess is that it is possible. The CRT is an analogue device. There must
be circuitry in the monitor that accepts the 4 digital signals and turns them
into 3 analogue signals to feed to the video amplifiers. So you should be
able to feed in a suitable analogue signal after said conversion stage.
Last time I was inside a similar Philips monitor, the main PCB was designed
for all possible versions, but only the necessary components were fitted. If
you can get the service manual for the version you want (with analogue
inputs) compare the PCB layout with the version you have to find out what is
missing.
When I had to do something like this, the hardest part was finding the
right switches and connectors that would fit on the PCB and line up
with the holes in the case.