Old monitor = no boot on G4? — #9

Post #9 by Bunsen

Source Forum	68kMLA
Category	Troubleshooting
Post Date	Thu, 16 Sep 2010 - 20:04
Original URL	https://68kmla.org/bb/threads/old-monitor-no-boot-on-g4.21297/

Post

force OS X to monochrome. (You can do that via the "Universal Access" settings control panel.)

Well, that I did not know. Thanks - that will make things a lot easier, at least in this application. I may still want to try a patch box for future uses.

If you just sum all three together / then you're also going to make for a pretty bizarre display. For example bright white will be three times brighter than, say, bright green

The circuit I found here seems to compensate for that somewhat, if I understand it correctly:

Code:

                        ____
RED    1 &gt;-+-----------|____|----+
          |  ____     82 ohm    |
          +-|____|-+            |
           180 ohm |            |
*RGND  6 -----------+            |
                       ____     |
GREEN  2 &gt;-------------|____|----+----------------&gt; VIDEO OUT
                      22 ohm    |
                       ____     |
BLUE   3 &gt;-+-----------|____|----+
          |  ____     240 ohm   
          +-|____|-+            
           100 ohm |            
BGND   8 -----------+

GGND   7 ------------------------------------------ VIDEO GROUND

HSYNC 13 &gt;----------------------------------------&gt; HSYNC

VSYNC 14 &gt;----------------------------------------&gt; VSYNC 

 GND  5 ----------------------------------------- GROUND

*incorrectly marked as BGND 6 on source page

I'd say just wire it up as it is, with the luminance line on blue

:?: There's no "luminance line" on VGA AFAICT - and the only connected color line is green