Interfacing Arduino with Macinstosh Classic 2 CRT

Hey Everyone

So I'm trying to do this:

Output composite video from the Arduino into the internal power connector of the Macintosh Classic 2.

I've found the schematics of the power connector: http://pinouts.ru/Power/macclassicpower_pinout.shtml

And I've found the technical manual for the Classic 2: http://members.optusnet.com.au/eviltim/macmp3/Mac_Classic_II.pdf

I've found this great schematic on hooking up the Arduino to output composite: http://pinouts.ru/Power/macclassicpower_pinout.shtml

Now I'm trying to figure out how to put everything together. I'm going to use the code from the Arduino Pong example (http://dailyduino.com/wp-content/uploads/2008/11/daily_duino_composite_video.txt) and refit it to output 512px x 384px for the CRT screen.

So my questions are:

  1. I guess the signal pin of the composite goes on pin 6 (vidout) of the Macintosh classic. Where does the ground/return of the composite go?

  2. Do I need to change the update rate from the Arduino Pong code to use it with the CRT monitor from the Classic 2?

Any help is appreciated.

Thanks!

its (line) sync is not really at all near NTSC, but faster, RS170 is like 15.6~7KHz mac's use 22.25KHz

it states that on page 23 of the Classic II pdf