11 May
2005
11 May
'05
4:37 p.m.
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