[comp.graphics] I need a VGA cable splitter !!?

pcb@cacs.usl.edu (Peter C. Bahrs) (01/16/91)

I want to have a wire comming out of my vga card and split into
two wires each with a female connecter.  Then I can connect my vga
to one and a overhead projector (Sharp QA 50) unit to the other; same 
output on both screens.

I know my card (compuadd) will handle this;  they are doing it in another
department.  But I can't find a splitter!?  

I just need a db15 rs232 male, some wire, and 2 db15 rs232 females.  The
pin connection I am not sure yet.  

Will someone please tell me where to get / how to make  one of these things?


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| Peter C. Bahrs                                                         |
| The USL-NASA Project                                                   |
| Center For Advanced Computer Studies      INET: pcb@swamp.cacs.usl.edu |
| 2 Rex Street                                                           |
| University of Southwestern Louisiana      ...!uunet!dalsqnt!gator!pcb  | 
| Lafayette, LA 70504                                                    |
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ong@d.cs.okstate.edu (ONG ENG TENG) (01/16/91)

From article <23098@rouge.usl.edu>, by pcb@cacs.usl.edu (Peter C. Bahrs):
> I want to have a wire comming out of my vga card and split into
> two wires each with a female connecter.  Then I can connect my vga
> to one and a overhead projector (Sharp QA 50) unit to the other; same 
> output on both screens.

I once needed the same thing, but couldn't find anything off the
shelf.  So I made my own.

> I know my card (compuadd) will handle this;  they are doing it in another
> department.  But I can't find a splitter!?  

You have to be care.  Driving 2 output devices is not recommended by
the card nor the monitor manufacturers.  Both the screens dimmed when
connected at the same time, showing sign of overload.
 
> I just need a db15 rs232 male, some wire, and 2 db15 rs232 females.  The
> pin connection I am not sure yet.  
> 
> Will someone please tell me where to get / how to make  one of these things?

No, it is not the normal db15 connectors.  Normal db15 has two rows of pins
(like those used by joysticks), the VGA connectors has 3 rows.  I went to
RadioShack and bought 2 females and one male, and connect them by the
following pins:
                   1 = red
                   2 = green
                   3 = blue
                   5 = ground (test) 
                   6 = red return
                   7 = green return
                   8 = blue return
                  10 = ground
                  11 = ground (color id) 
                  12 = ground (monochrome id) 
                  13 = horizontal sync
                  14 = vertical sync

I was warned about interference, but got none.  Maybe that's because
there are not enough computers in my building.  But I did went ahead
and got some sheilding material from RadioShack and taped them 
around the Y-connector.  The whole thing cost more than $20.