DECmate III and Rainbow 100+

[Tony Duell]

> The sync on blue statement comes straight from the PRO technical
> manual -- but I missed part of it.  Re-reading and double checking
> with the Pro-380 schematics produces the real answer, which is:
> 
> 1. The monochrome video line always has sync on it.
> 2. If you don't have the EBO installed, the blue signal is a copy of
>    the monochrome video signal.
> 3. On the Pro-350, if you don't have the EBO installed, sync also 
>    appears on the blue signal.
> 4. On the Pro-380, sync always appears on the green signal; if you
>    don't have the EBO installed, that's all there is on that wire.
>    The blue wire never carries sync on the Pro-380.
> 5. If you DO have the EBO installed, then sync is on green.

Eeek. How non-simple....

On the 'Bow : 

The mono signal (which becomes the green signal when you use it with a 
single colour monitor) carries the sync always.

If you don't have the colour card, the R and B signals (and the 
green-only signal, used for a dual monitor configuration) carry nothing. 
In fact they just go to pins on the colour card's connector.

[Yes the colour monitor cable for the 'Bow is different to the one for 
the Pro...]

-tony