[Coco] Stable colours

[Luis Antoniosi (CoCoDemus)]

On Tue, Sep 30, 2014 at 12:48 PM, Frank Swygert <farna at amc-mag.com> wrote:

> artificial artifacts


You are talking about the coco1 SG6, the infamous red that is in fact
orange but if you are luck you get it blue...

VCC emlator does a crap job emulating them. I prefer the MESS which is
close to the NTSC but the mess is much more complex.

Also, I use internal RAM for 2 lines only. I have one incoming line (from
genlock) and one outgoing line (vga output). Those lines are stored/load
from/into the main SDRAM (which is slow and must be loaded/stored in burst
mode).

In one clock cycle I can only have one pixel. I cannot get the next. The
maximum I can keep the previous pixel in a variable. So at best case it
would look like VCC, shifted because the first pixel wont the artifacted,
suppose:

00 10 10 10 00 00


The first 1 would remain black as the 0 would be blue, or red, or
orange...what would create hard edges.. :P






Luis Felipe Antoniosi