On Tue, Jun 14, 2016, tony duell wrote: > > 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.
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