8.12 Video Turtle

Connecting a Video Turtle to the Falcon Video Out

Hello!

Well, after a fairly long Saturday last weekend, in which my buddy and I went over the ST RGB signals with a fine tooth comb, two o-scopes. We do have some success!

First, we found that the Amiga itself outputs a 1.5V p-p with a 2V DC bias. The ST(1040STf) we measured, does indeed have a 1.8V p-p with a 1.2V DC bias, on the RGB signal levels.

In both systems, the sync signals were TTL levels. No biggie there.

We also found out that the cable I had from Redmond Cable, the supposed "new" one, was all messed up. The RGB lines were all tied together, and a sync line had a resister.

We also discovered a mis-print in the manual, DUH, the vertical sync polarity jumper was reversed, so that finally gave us a very stable picture.

But, the cable I am currently using, has just 33 OHM limiting resisters on the RGB lines. So, I get a real good picture, but I am limiting the picture to B&W right now. I have a new cable that brings the ST RGB to a level of .72 V p-p.

The moral of the story, don't give up, and pull out the big guns of debugging, and test the jumpers!!!!

I can't wait to have the Lost Blub demo on a 35" S-Video TV, or on an LCD Projector, with S-Video inputs!!!!!!

The saga continues........

Jim W. Krych