GIGI questions

[Tony Duell]

> Correct.  It was designed for the DEC VR241, the same color monitor
> that the Pro series uses.  Those have RGB inputs, sync on green,
> US TV scan parameters (timing and line count).

I wondered about that, but I thought it was such an obvious choice that 
Witchy would have mentioned it if it was a recomended monitor. From what 
I remmeber there's a switch on the back to select between sync-on-green 
and separate (composite) sync.

The VR241 is, of couree, a Hitachi chassis. A rather unpleasant design, 
actually. The PSU is driven by the horizotal oscillator, via a winding on 
the flyback IIRC. Of course the PSU powers the horizontal section. To get 
it started, there's an astable on the mains side of the PSU that's 
disabled after a short time, by which point the horizontal side should 
have got going.

So for the PSU to work, the horizontal section -- the most unreliable part
of any monitor -- has to be working too. Debugging it is a right pain -- I
found that the hard way. Oh, and the deflection driving IC, vertical
output stage, etc are part of a thick film hybrid module on the scan PCB. 

Oh well...

-tony