UK 1200 in the US?

[meega]

Use NTSC Monitor driver. Job done.

Edit: although, apparently, the UHF output thingies aren't the same - but if you are using a real 15KHz RGB monitor then that is irrelevant.

[meega]

Pressing the space bar when the Early Startup screen is showing will toggle between PAL and NTSC, but the machine will still boot up with whichever monitor driver you have Saved in Screenmode Prefs.

[meega]

>>does the A1200 have a composite video out already?

Yes, it does, and it is colour.

[meega]

Please explain why my 21" Sony Trinitron video monitor (no UHF decoder) displayed Never Twice the Same Colour hue changes when using NTSC screenmodes, and correct PAL colour when using PAL screenmodes, from the composite output of my A1200.

[meega]

Colour encoding problems are inherent in the original NTSC standard. The whole point of PAL is that it eliminates those swings of colour (so no hue control but a saturation control instead) but it does require more complex and so more expensive circuitry. The US did not choose NTSC for quality, but for cheapness. Any colour is better than monochrome, yes?

Edit: anyway, back to the OP once again, if you use an RGB monitor (or use RGB input into a suitable TV) then you should not experience any such problems.