DECmate III and Rainbow 100+

From: Paul Koning <>
Date: Thu Feb 24 08:49:16 2005

>>>>> "Tony" == Tony Duell <> writes:

>> It's in the Pro 300 technical manual, on Al's website.
>> The video connector is a bit weird. It carries both a mono
>> (grayscale) signal with standard sync, and also on separate wires
>> an RGB signal with sync on blue (not on green). Don't know if the
>> Rainbow and DECmate have a color option, but the Pro does and
>> that's where it goes.

 Tony> I would check that very carefully (in other words : It doesn't
 Tony> agree with what I've seen).

 Tony> The standard colour monitor for this series of machines is the
 Tony> VR241. It's acatually a Hitachi chassis with a vile PSU
 Tony> design, but I digress. It can take RGB + separate composite
 Tony> sync (on 4 BNCs) or RGB with sync-on-GREEN. I have the
 Tony> schematics to prove the latter statement...

 Tony> My VR241 came with a Pro350. The Pro's video cable had 3 BNCs
 Tony> on the end, and certainly used sync-on-green (there may well be
 Tony> sync on the other video signals too). IIRC the Pro outputs a
 Tony> separate mono composite signal that can be used to drive the
 Tony> VR201 mono monitor.

Yes, that's what I said: there is an RGB output AND a mono composite
output on the 15-pin connector.

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.

Wow. Thanks Tony.

Received on Thu Feb 24 2005 - 08:49:16 GMT

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