Thread
Macintosh 12" RGB Display - Composite?
Hmm. I will crack it open on Monday and see what it's got in there. googled for about an hour today and what I came up with (as far as converting composite to analog rgb) was a bit out of my skill set as far as microchips and bread boarding. I can solder, but IC's are just not something I am familiar with.
Considering you can use it to display RGB computers like Amiga's or Atari ST's I guess it should be possible to hook up any RGB device. Considering that RGB gives a much better colour image then composite. You should try to hook up your device through there rgb ports. You will need to make custom cable though!
Now that's a great notion for a hack, Component Video -> RGB would be very interesting.
One of my Mac cables is 5 BNC, so the signals should be available . . . no coffee yet so no research for a while . . .
. . . tapping into all the proper points on the controller board from an A/B switch just might work out.
One of my Mac cables is 5 BNC, so the signals should be available . . . no coffee yet so no research for a while . . .
. . . tapping into all the proper points on the controller board from an A/B switch just might work out.
[citation needed]Considering you can use it to display RGB computers like Amiga's or Atari ST's
[citation needed]the refresh rates are non-standard to NTSC
No, I'm not nit-picking - this is an area of interest to me and I would like to see documentation if possible
TV & Monitor Repair FAQ -> Notes On Video ConversionComponent Video -> RGB
I'll bet there's a link to a component-RGB converter schematic in there someplace. It shouldn't be too complex - as you say, all the signals are available.
There are IC's that will separate composite and component into RGB, that part is simple enough. Very few RGB computer monitors scan anywhere near the 15.7 kHz horizontal of NTSC though, most are close to double that or higher. Displaying NTSC on one of those requires a scan converter, it digitizes two interlaced fields into a frame in a RAM buffer and then converts that back to a single non-interlaced frame at the scan rate supported by the monitor. It's possible to do, but certainly not worth the effort unless you have a very specific need.
I found specs for the M1299 RGB monitor in about 10 seconds with a search engine.
http://www.monitorworld.com/Monitors/apple/12colordisplaym1299.html
Fixed frequency, 512 x 384, horizontal 24.48 Khz, not even close to NTSC.
http://www.monitorworld.com/Monitors/apple/12colordisplaym1299.html
Fixed frequency, 512 x 384, horizontal 24.48 Khz, not even close to NTSC.
For those who are curious, here's an excellent example of what is involved in doing this.
http://elm-chan.org/works/sc/report.html
This circuit could be modified to work on a 24 kHz monitor if one was inclined to do so, but it's quite a lot of work. Mr. Chan's creations are very impressive, all hand assembled on perfboard, but it would have been FAR easier to duplicate if he had used a PCB layout instead.
http://elm-chan.org/works/sc/report.html
This circuit could be modified to work on a 24 kHz monitor if one was inclined to do so, but it's quite a lot of work. Mr. Chan's creations are very impressive, all hand assembled on perfboard, but it would have been FAR easier to duplicate if he had used a PCB layout instead.
NTSC video is broadcast and displayed at 640x480 with a refresh rate of 60hz. On the Macintosh the original....[citation needed]
http://support.apple.com/kb/SP421
Ignore me. I was thinking of that dumb 66.7hz refresh rate they used. xx(
You aren't kidding about that being alot of workFor those who are curious, here's an excellent example of what is involved in doing this.
http://elm-chan.org/works/sc/report.html
This circuit could be modified to work on a 24 kHz monitor if one was inclined to do so, but it's quite a lot of work. Mr. Chan's creations are very impressive, all hand assembled on perfboard, but it would have been FAR easier to duplicate if he had used a PCB layout instead.
That's funny.