The problem with the Power R is that it doesn't deliver a standard signal. Both the horizontal scan rate and the resolution are nothing like CGA or EGA, but may have overlapped with some monitors for other computers. But I suspect that many were modified displays for the Mac.
As I wrote several years ago at http://www.vintagemacworld.com/build_own.html, we need more information about old TTL monitors and adapters. I don't have a lot more concrete information today than when I wrote this:
"Chapter 8: Video display
This chapter is disappointingly short of detail -- the third party Mac display/video card market was thriving by this time but few options are mentioned. A kit for building a TTL adapter for 128 and 512 Macs (made by a company called ATS and presumably the same as the adapter mentioned in Larry Pina's book) and the Power R cable/adapter for compacts are discussed briefly. There is a reference to a series of "Hackintosh" articles in Computer Shopper, a US magazine, on homebrew TTL video adapter and monitor options -- does anyone have copies?."
Perhaps a few old magazine reviews will throw up information about displays that work with the Power R?
As I wrote several years ago at http://www.vintagemacworld.com/build_own.html, we need more information about old TTL monitors and adapters. I don't have a lot more concrete information today than when I wrote this:
"Chapter 8: Video display
This chapter is disappointingly short of detail -- the third party Mac display/video card market was thriving by this time but few options are mentioned. A kit for building a TTL adapter for 128 and 512 Macs (made by a company called ATS and presumably the same as the adapter mentioned in Larry Pina's book) and the Power R cable/adapter for compacts are discussed briefly. There is a reference to a series of "Hackintosh" articles in Computer Shopper, a US magazine, on homebrew TTL video adapter and monitor options -- does anyone have copies?."
Perhaps a few old magazine reviews will throw up information about displays that work with the Power R?