OT: faking a VGA display

[Jules Richardson]

Some of you here might know this :) I've got a system here where I need to 
make it think that there's a monitor plugged into its VGA port even when there 
isn't (long story).

Plugging a real CRT into the port even when that CRT is switched off and 
unplugged from the AC supply works, so there's obviously some way of doing it.

Measuring the CRT above (switched off, unplugged from AC, and unplugged from 
the device) with respect to the VGA connector's shield gives me the following 
readings:

pin  sig      value
  1   R        76ohm
  2   G        76ohm
  3   B        76ohm
  4   NC       GND
  5   GND      GND
  6   GND      GND
  7   GND      GND
  8   GND      GND
  9   NC       infinite resistance
10   GND      GND
11   NC       GND
12   DDC DAT  8.1Kohm (initially 7.6Kohm, rose at first then steadied)
13   HSYNC    4.6Kohm
14   VSYNC    4.7Kohm
15   DDC CLK  8.1Kohm (initially 7.6Kohm, rose at first then steadied)

Any suggestions? Do I just need 76ohm resistors to ground on the RGB lines 
(and possibly 4.7Kohm resistors to ground on HSYNC and VSYNC)? Or is there 
likely something more subtle going on that I need to incorporate into my 
"fake" connector? (Given that VGA supplies no DC out, it can't be anything too 
complex!)

cheers

Jules