Dear Alex, > And yes, it has two crystal and a subboard for dividing I think. The schematic 251103, right side, features a "clock unit" as a "black box" with the following pinout: 1 ground 2 dot clock (8*phi0) 3 bus clock (phi0) 4 +5V 5 ground 6 color clock (phi color) In the table below this "black box" in the schematic, the figures for dot clock and color clock are swapped. > So it gets more complicated than a normal C64... As I don't have an SX-64 or the schematics for this subboard, I'm passing a copy of this message to the cbm-hackers mailing list. If there are no PAL SX-64 owners on the list who could help you, you could try to construct some sort of a schematic diagram for the subboard (even just the part numbers would help a lot). Marko I left the following as additional information for the cbm-hackers crowd: > Here´s a text from Ray that could make you see better the situation... :) > > ------------------------------------------------------------------------ > Alex, > The more I dig into this problem, the more I realize a conversion is > just not that common, but there certainly are PAL SX64 computers out > there. I'll give you the information I have based on this hand drawn > Commodore service manual. I'll have to agree that there are no > jumpers... at least none that I could find. However, it appears there > are several chips that need to be changed, and the master oscillator > is a sub board with a crystal on it. Changing to PAL might require > changing that entire board which this book identifies simply as "clock > unit"... no numbers. The book doesn't show a diagram of that board, > but it appears to be a master oscillator and a set of dividers to > generate the three clock signals. It also appears the NTSC PLA chip > UE4 (numbered MB112A101) needs to be changed to a special PAL version > (numbered 7700-001). With the wrong clock signals, you will have > incorrect colors out of the VIC. It doesn't look like an easy mod. Two > people that regularly post to the newsgroup comp.sys.cbm are Nicolas > Welte and Marko Makela. They are both engineering techs that know the > inner workings of the computers much better than I do (I'm just a > repair tech) and would be able to tell you exactly what you need to > know to do that modification. They live in Europe and would have the > PAL versions of the SX anyway. I've only seen the NTSC version myself. > Good luck! > > Ray - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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