On Monday, August 29, 2016 at 6:11:28 AM UTC-7, wrote:
On Monday, August 29, 2016 at 2:18:30 AM UTC-4, Andy Burns wrote:
whit3rd wrote:

VGA uses three pins to send screen capability data from the monitor
to the video card

The original monitor seems NOT to be connected by VGA, it's possible the
slot machine will just assume the CRT is the correct one to display
whatever signals it outputs, rather than looking at EDID data the way a
PC would.

will that affect what i'm trying to do?

Maybe; the video MODE information never gets confused when the ID pins
are read, but if those AREN'T in use, the video output and the sync signals
might be misinterpreted as the entirely wrong sync rate, or resolution. The
description of the picture being offcenter of the screen does sound like a
mode mismatch between monitor and video 'card'.

So, the monitor walks the picture off the left screen edge at 5 milliseconds, but
the picture isn't completely sent until 8 milliseconds. The monitor just
decided on the wrong horizontal sweep rate.

In the early days of multisync monitors, Apple and IBM and third parties all did
the timing according to whims. Adaptation was a BIG issue.