[Coco] S-video Prospects...

[Stephen H. Fischer]

Hi,

John Kowalski wrote:
> At 07:09 PM 07/01/2006 -0800, Stephen H. Fischer wrote:
>> The CoCo generates both fields to be the same, or is it just generating
>> one of the fields?
>
> The CoCo's video is a little different than the standard interlaced NTSC
> video.  Instead of alternating two interlaced fields, it simply repeats a
> complete non-interlaced frame each field.
> The reason for the visible gap between scan lines is because the
> TV/monitor recognizes that the video is not interlaced, and therefore
> does not shift the scan lines up & down in position each alternating
> field.
>
> The result is simply a non-interlaced 60Hz 263 line display instead of a
> 30Hz 525 line display.  All 8-bit computers and video game consoles were
> this way, as are today's "TV game" toys.

What are the results of delaying the First Horizontal timing pulse after the
Vertical blanking period. This is how the second field is shifted down to
be interlaced with the first field I remember.

Does this produce a display with each CoCo line displayed twice resulting
in letters that are twice as high but a better display.

I am sure someone has tried this before without good results or I would have
heard about.

>> My TV seems to reduce this effect which is good.
>>
>> In looking at your pictures, to my eyes they seem to be very present.
>
> The difference is that I wasn't using a TV.  My photos are actually of an
> Amiga monitor which has a fine dot pitch.  TVs have a wider beam, so the
> black gaps between scan lines will be less noticeable than in my case.
>
>                                         John Kowalski (Sock Master)
>
> http://www.axess.com/twilight/sock/

Did the Amiga have a factory installed S-Video input or did you add one?

With my high end TV there are enhancements to improve the displayed
picture that are lacking on your Amiga.

That may be why I rated the CoCo S-Video Displays higher than you.

Stephen H. Fischer