On Dec 15, 2010, at 4:42 PM, Gregg Eshelman wrote: > The main gotcha with connecting a new monitor to a really vintage Mac (mostly > 68k CPU ones) is they used sync on green while the VGA standard (and its > various extended modes) used separate or composite sync signals. Composite > sync simply connects the horizontal and vertical sync lines together. > > Connecting a modern VGA monitor to a two row 15 pin Mac video port that > *doesn't* use sync on green is easy. Either find the sense pin arrangement > that matches a resolution the old Mac supports then build an adapter just for > that one use, or buy a multi-resolution Mac to VGA adapter that has DIP > switches or a rotary switch. Those are rather common and inexpensive. With a > DIP switch style, typically the ones with more switches (IIRC 10 of them) > support more resolutions and have the diodes for the extended sense pin > codings. > > If your old Mac uses sync on green, then you need a special adapter that > separates the sync signals from the green signal. Griffin made one such which > could adapt any modern analog VGA monitor to ANY Mac with the 2 row 15 pin > video port. It only cost around $50, which is more than any Mac that outputs > sync on green video is worth. Buying one of those used is the way to go, > unless you can find a circuit diagram to build a sync signal separator into a > homebrew monitor adapter.
I tried a IIsi (Sync-on-Green) with a couple of LCD monitors and it worked. All I needed was a basic Mac video to VGA adapter. I suspect Sync-on-Green has been added to some modern monitors as the cost is trivial. The biggest problem I encountered as that the IIsi is limited to 640x480 (besides full page display) and the 1600x1200 LCD monitor either displays it scaled up to fill the screen, in which case it's all fuzzy, OR It can be displayed in the middle of the screen. It's sort of hard to look at such a small bit of screen. :) Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/
