Scott Alfter wrote:

>> The service manual lists the following signals as being valid when in TTL 
>> (EGA/CGA) mode:
>>
>> RA GND
>> r
>> R
>> g
>> V.D
>> H.D
>> G
>> B
>> b
>>
>> So, what is that trying to convey?  The V and H sync are somewhat
obvious, as 
>> are R,G,B.  So, what are the lowercase r,g,b? Inverted polarity?  Different 
>> levels?
> 
> r, g, and b would be the low bit for each component in EGA mode.  g should
> serve double duty as the intensity signal for CGA mode.

Yes!  Thanks largely to Mike Mahon's kind review of the schematic, I have 
things working on the first victim - err, computer.  The intensity function 
does seem to be multiplexed on the 'g' pin.  Last evening, I built an adapter 
that lets me view the RGBI output from the 9-pin connector on my C128 :-).

This evening I'll drag out a Mac adapter and see if it cooperates with the IIGS.

> I think some of the front-panel switches on the monitor might also need to
> be flipped to enable EGA or CGA usage.  Since I've only used mine for VGA
> and analog RGB, I can't confirm this directly.

I believe that's correct for EGA specifically.

For prosperity, here is the wiring scheme that I'm using:

DB9M	HD15F	Signal

1	1	GND
2	2	r
3	3	R
4	13	G
5	14	B
6	5	g / Intensity
7	15	b / Mono
8	12	H Sync (and, I believe H/V composite)
9	10	V Sync

For the C128, the secondary r and b are probably superfluous.  On a GS, ditto 
for V sync.

This is a handy monitor to have around.  Wish there was a contemporary unit 
available with the same versatility!

Steve
--- SBBSecho 2.12-Win32