Ok, I'll just go the composite route then. Now my next question(s)...will the composite output of the 1200 automatically "turn off" when a non-15KHz mode is displayed (e.g. my Workbench screen is Productivity mode)? Or will the 1080 show a scrambled screen?
Also, is there a way to have all 15HKz modes display solely on the 1080 and all the non-15KHz modes display solely via RGB/VGA? Would really like as seamless a "dual display" setup as possible.
The composite output won't turn off and it will display a scrambled screen on a 15KHz monitor. What you could do is either turn the monitor off when this happens (it definitely won't do it any good keep turning it on and off), or unplug the composite output from the back of the Amiga every time, or, install a switch somewhere on the cable that turns the signal on/off. Some monitors may have a video channel selection switch so that could be pressed instead. The thing is, I wouldn't want both monitors on all of the time as it's wasting power anyway so I don't quite understand what your after. Also, those 15KHz CRT's have that whistle noise which would be very annoying if on and not being used.
The simple obvious solution is to just hook up the CRT to another Amiga so you can then pick which one you want to use. Alternatively, hook them up to the same machine and edit your Startup-sequence so that holding down the left mouse button boots into a games launcher in a 15KHz mode (TinyLauncher for example), and holding down the right mouse button boots into Workbench in a 15Khz mode (for your graphics applications). If you boot without holding any mouse buttons down then you get your normal 31KHz Workbench for your NEC LCD screen. This saves all the fiddling about, and it's what I'd do.
What you don't want to do is to accidentally display these non 15KHz modes on a 15KHz monitor because it's not supposed to be particularly good for them.
So, in your 15KHz Workbench boot option (RMB) you'll want to make sure you only have the PAL/NTSC/Euro36 driver in Devs/Monitors. Of course, taking this further there will be some of your software configured for the higher resolution 31KHz modes and these save their settings somewhere (usually ENVARC:) so you could have an alternative ENV with these 15KHz settings for when you boot with the RMB pressed down (I'm talking besides the obvious screenmode.prefs which would have to be switched).
Or, you could have different boot partition for 15KHz. There is a little shell program that can change the boot partition priorities, so this could be used with the mouse detection at the beginning of the Startup-sequence and cause a reboot into the 15KHz Workbench. Of course it will remember it, so you'd have in your sequence either something that reverts it back to your preferred boot (31KHz) or detect the buttons again at the beginning. For example, you might forget which mode you left it on....well, it doesn't matter really, just boot up and hold down both mouse buttons together and it'll boot into 31KHz. You can even detect a joystick press, or a key combination instead. It's all on Aminet, and your options are endless in what you can achieve.
