kwf@ncsu.UUCP (Kenneth W Fernald) (07/30/85)
Last night, through an act of stupidity, I turned-off my 1541 while my c64 was still on. After turning the c64 off and on again, the screen went light blue and stayed that way. I get no response from the keyboard. Does anyone know what chip was mostly likely destroyed and where I might get another one? Please respond by mail. Thanks in advance. Ken Fernald (...!mcnc!ncsu!kwf)
dlc@lanl.ARPA (08/07/85)
> . . . After turning the c64 off and on again, the screen > went light blue and stayed that way. > Ken Fernald (...!mcnc!ncsu!kwf) I'm not too confident about remembering chip numbers, so let me preface what I'm going to say by warning you the chip numbers may be wrong. The C64 uses enhanced VIA (versatile interface adapter) chips for several uses, including the user port, the joystick/paddle ports, the keyboard, and the serial port which runs the 1541 and printer. What you probably did, by moving your hand around the power switch in the act of turning the machine off and on, was discharge some static electricity through one of the joystick ports which zapped one of the 6526 chips. They are 40 pin chips which are under the lefthand side of the keyboard. In newer revision levels of the C64, they are soldered, so it can be a pain to replace one. You should be able to order one directly from Commodore in West Chester, PA, at about $10 each, or a local dealer with a repair shop can fix it for you for about $40, I would think, not much less than a new C64 costs. The joystick inputs are unbuffered, so the VIA is very vulnerable to fingers touching the pins. It would be a good idea to keep joysticks plugged in both ports at all times, or, if you don't use joysticks, to cover the ports with tape or dummy connectors. If you only use one joystick at a time, I'd suggest you buy a second one just like it for the other port anyway, it's cheaper and easier to find than a 6526 chip. The enhancement of the 6526 was over the 6522, which is used in the VIC-20 and that more modern, powerful(?) machine, the Apple Macintosh.