CompuServe Messages

Abdullah, My knowledge is fuzzy on the subject of the color monitors, but I'm fairly sure they are okay. Here's the scoop: NTSC color (what Ami and TV uses) uses a horizontal frequency of 15735 Hz and a vertical frequency of 59.95 Hz, and the internal oscillators of the TV/monitor sync to that. The IBM monochrome system uses a different set of frequencies. When you force a IBM type monochrome monitor to sync to the NTSC horizontal frequency, the deflection yoke and HV supply (which are tuned circuits) are being operated far off their resonant frequency. This causes a drastic change in their impedance, which in turn requires more power to drive them. The end result is more heat dissipated in the deflection circuitry and a heavy load on the power supply. Depending on the monitor, any one of several things could happen: you might not even be able to sync it, you could sync it but not have enough deflection in one or both directions, you could sync it and everthing looks okay until the horizontal output circuitry or power supply fails, or you could sync it and everything would work fine for all time. Which will actually happen is anyone's guess. Now if the color monitors use near NTSC sweep frequencies — and I believe they do — you have nothing to worry about… although you will have to obtain a special cable, as has been pointed out. And, in any case, your Amiga power supply is in no danger. Hope this helps! Rick