On Sat, 18 Nov 2017 18:44:07 -0500 william degnan via cctech <[email protected]> wrote:
> On Nov 18, 2017 4:09 PM, "Douglas Taylor via cctech" > <[email protected]> wrote: > > > > 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 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"
