Re: Apple 'Monitor 100' works on GS

[shack@deimos.frii.com (Randy Shackelford)]

In article <20SEP199603020059@vax2.concordia.ca>,
Mitchell Spector <spec@vax2.concordia.ca> wrote:
>    This is rather interesting. A local person, having come across a pair
>of Apple IIgs's and RGB monitors, asked for the pinouts to GS's RGB port
>(seeing that he lacked a cable to connect the monitor and wanted to build
>his own). I assumed he must have received an AppleColor RGB display, but
>after connecting things up, he reported the screen worked fine _but_ colors 
>weren't matching up. I asked for some details on the RGB monitor; he told 
>me it was an Apple model 'A9M0308', beige colored case and pointed out it
>had a motorized tilt screen. If I'm not mistaken, this is the Monitor 100.
>A *digital* RGB display for the Apple III and IIe (with RGB adapter card).

Hmm a dealer told me I would roast something if I tried to connect my 100
to a IIgs. But that was in '86 when IIgses had just hit the streets so
guess he coulda been wrong.

>    A few years ago, I managed to do the reverse. I plugged an analog RGB
>(AppleColor RGB) from a IIgs, into an Apple III. The results were similar,
>a perfectly viewable image but with color information not matching up.
>How is it an analog and digital RGB screens can be interchangable? Do these
>monitors have some sort of alternate mode, or the Apple III and IIgs
>themselves have some way of sending out different video signals.

This would seem to be along the lines of the saying "a broken clock is correct
twice a day". There are some signals getting through and doing the right
thing but not enough there to really make it work. I don't think I'll
experiment beyond trying the 100 with the III and III plus.

Once upon a time I was told that 100s have a switch inside to switch them
from digital to analog. On one of the several times I had to crack mine open
to fix the electric screen tilter, I spotted the switch. Later on I heard
the switch is to get the monitor to display more colors when it's on an
Apple III. I think that's more plausible.
-- 
Randy Shackelford                                 US Air Force officer
shack@frii.com                                    and Apple aficionado