On 2012-09-12, at 22:35, Gerrit Heitsch wrote: >> Does one have to care about the relation of the phases of both outputs? > > There was some reason why they didn't use 2 crystals in the C64 but had to have the color clock and the dot clock be related to each other. On 2012-11-26, at 20:04, Gerrit Heitsch wrote: > Also, some people claim, that the old clock generator (74LS629 and MC4044P on the 250407 boards) produces less jitter than the 8701. I had a moment of inspiration today (after Michau asked about the SX ROMs) to check how it is done in the SX (I thought it was like in the older 64s) and.. it occured that there are actually /two/ crystals piggybacked one on another and just three 74LS chips next to the passive stuff on the daughterboard called "clock unit". This means much more "generic" solution than the 8701, which I try to get rid of and even better in this terms than the hard to come by chips from the "discrete" clock generator in earlier C64 boards. Unfortunately the schematics show it as black box only. It looks like it wasn't made by CBM but rather sourced out of house. It bears a "TOYOCOM" marking on the PCB. Does anyone know if a schematic for this "clock unit" is available somewhere? -- SD! Message was sent through the cbm-hackers mailing listReceived on 2013-05-02 21:00:10
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