knudsen@ihnss.UUCP (09/07/83)
I am posting this response since ARPA's great mail demons seem unable to follow a path: I doubt you would have much trouble with 50-cycle AC, provided of course you sstep down the European 220 V to our 120 (such adaptors are readily available). Most home computers derive all timings from the internal crystal clock, including the 60-Hz vertical TV seep rate, so the AC power line is not involved. You might have some overheating o the power transformer and/or cooling fans, and the fans will run 1/6 slower. Depending on the size of filter caps in your CRT monitor, you might get a 10 Hz flicker (slight) on the CRT brightness. Make sure your disk drive motors are DC (most are these days), not AC, or your disks will run at 5/6 speed which might wreak all sorts of havoc... Enjoy your trip -- mike k
stevek@umcp-cs.UUCP (09/09/83)
and from another note I saw on this net ditto for the IBM PC but the display problem is a more serious one. One solution is to use a DC video display (they run $70 from a local surplus dealer for a new 10Mhz display) which will use our (60Hz) synch. At least for the apple (II+) it is "easy" to modify (by jumpers on the motherboard) for 50Hz synch. Remember that 60Hz USA standards use 15750Hz horizontal scan = 512 lines per frame, the 50Hz European standard works out to something like 600 lines per frame (I do not remeber the exact number but 600 is a ballpark value) so that if you try to use a 50Hz monitor if it works at all, more than "a little" wiggle will occur - it will probably not work at all (I could be wrong). The bottom line is that if you buy a "system" micro like the apple or IBM PC they planned it for world use. As far as the others that supply a little transformer that plugs into the wall 1) find out if the manufacturer has a 220VAC 50Hz replacement 2) unless the video can be jumpered; a 60Hz DC monitor used ; an external terminal (50Hz) is to be used ; or if one of the video display chips (like the 6845) is internal then a prom or patch program to reset it for the 50Hz scan. In any case good luck, I hope I have not gone into more detail than is needed. Stephen Kogge Department of Computer Science University of aryland
stevek@umcp-cs.UUCP (09/09/83)
Sorry about that but for some reason the first line seems to have been lost from my follow-up. It should have read For the apple (and from another note on the net the IBM PC) there should be no problem with the power supply - just slide it to 200VAC. Stephen Kogge University of Maryland Department of Computer Science