greg@utcsri.UUCP (Gregory Smith) (05/05/86)
[--------------------------------] My brother is looking to buy a used C64. I remember that when the system first came out, there was a serious problem with the colour generator chip - if a green letter was displayed on a red background, say, the result was unrecognizable. The problem occurred with any two different *colours* - dark blue on light blue was OK, green on white, black on yellow etc were ok. Has this ever been fixed? If so, when? Any details would be appreciated. I seem to remember that the C64 has no RGB outputs, and they cannot be added because the NTSC signal is partially encoded within the video chip and unencoded RGB signals are not available externally to the chip. Is this true? For video-minded people: Apparently the line-scan period was an exact multiple of the color subcarrier period. It should be n/2 times the subcarrier period, where n is an odd number. Displaying 80 columns in colour using NTSC video is intrinsically very difficult, because the luminance signal spectrum will overlap the colour subcarrier significantly - the dot rate would be about 15MHz. If anyone knows the technical details of how this can be overcome, I would be interested in that, too. Please e-mail if possible - Thank you. -- "Canabee be said2b or not2b anin tire b, if half thabee isnotabee, due2 somain chunt injury?" - Eric's Dilemma ---------------------------------------------------------------------- Greg Smith University of Toronto UUCP: ..utzoo!utcsri!greg