18 Nov
2017
18 Nov
'17
3:54 p.m.
On Sat, 18 Nov 2017 18:44:07 -0500
william degnan via cctech <cctech at classiccmp.org> wrote:
On Nov 18, 2017 4:09 PM, "Douglas Taylor via
cctech"
<cctech at classiccmp.org> wrote:
The "issue" is "Sync-on-Green". Many *NIX and DEC systems that have
RGB
output do NOT use a Hsync signal - but rather sync is placed on the
"Green" channel.
If you use any monitor capable of "sync-on-green", and it should work.
Best,
Lyle
--
Lyle Bickley
AF6WS '73
http://bickleywest.com
"Black holes are where God is dividing by zero"
I have a couple of vaxes that output 'unique' video, Alpha 3000
300,
Alpha 3000 400, Vax 4000 VLC, and Vax Station 3100 M76.
The Alpha and VLC each have a 3W3 type of connector and the 3100
has a 15
pin DEC designed connector.
What does it take to connect these to inexpensive, modern VGA
light
weight monitors?
Doug
I have played around with that problem. If you have a converter to
get into a VGA port a newer high-end vga display will be able to
adjust, but not a cheap one. Because I use my vice vga/digital
display for mode stuff, I use a huge SGI color display for all of my
3w3 outputting systems and I just switch the cable around. If you
could imagine 5 or 6 systems clustered around the one display.
I am sure someone here has a technical explanation, but in a nutshell
the 3W3 world signal isn't the same as a standard vga and cheap vga
displays can't handle the refresh rate. Someone will prob. refine my
answer but that's why you can't just stick an adapter on there.
Bill Degnan
twitter: billdeg
vintagecomputer.net