[Coco] Last video I promise... :)

[Steven Hirsch]

On Fri, 28 Nov 2014, Luis Antoniosi (CoCoDemus) wrote:

> The customization is about the front porch, the code now is pretty stable
> to be generic. But yours seem to work. Steven Hirsch had to change on him.
> He didn't report about noise. So I can't tell if is a particularly from
> yours or if this board has indeed noise. Until my mules decide to cross the
> border I can't help you on this.

Are you experiencing the legendary efficiency of Canada Post?  If you're 
in the Montreal area, you could have driven down to Burlington, VT and 
picked up one of mine :-).  Still can, if you like!

I see some noise and instability on the Coco 3 display for about a minute 
after I power up the board, then it cleans up and is fine from that point 
on.  Something, somewhere is heating up and slowing down?

> BTW, Steven has found out theat the correct values for the sync resistors
> are 47 ohms instead of 82. I doubt this could be the source of problem.

For me, that was an all-or-nothing issue.  With the 82-ohm resistors many 
of my monitors failed to recognize they were being driven.  I suspect that 
almost anything between 47 and 68 ohms would be fine.

> You don't need the LM1881, the 680K and the 2 caps if you're not planning
> to connect any other computers on it.
>
> The scalines help improve the colors. You may turn them on, use a dip
> switch. I have changed the dip switches, the scanline is now the label
> shrink.

The scanlines are my favorite bit :-).  I bought a little gadget last year 
that injects scanlines into a VGA monitor and found that it made almost 
all classic computer displays look nicer.

Steve


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