On 2013-05-04, at 19:41, Gerrit Heitsch wrote: >>>> I am wondering if anyone knows (before I start disassembling the SX in order to experiment) whether this effect can be caused by the differences in the clocks generation methods between regular 64 and the SX or something else (like the output amp). >>> >>> How is the internal monitor hooked up to the SX-64 video output? Y/C or CVBS? CVBS would explain some of the artifacts. >> >> You don't see the ugly effect on the internal one. The resolution of that delta tube is probably too poor there to notice much. >> >> According to the schematics, the internal one is fed with Y/C. I did a quick test and disconnected the internal display checking if it would affect the picture on the external one but no change was visible. > > Could be the same problem as on the C16. There the Chroma-Signal imprints itself on LUMA just by the traces running close together that feeding the monitor just LUMA will get you a color picture. If I disconnect the CHROMA, the artefacting is gone together with colour. So CHROMA on the outside of VIC has to be the reason (yeah, no clocks phases and co.) but in a different way than on the C16. > Using it as Y/C will get you what your pictures show. Even worse on a TFT. > > So maybe you need to check the SX64 boards and see how both signals are routed between VIC and video output. While of course both signals are next to each other on the VIC already, the output stages are close to the VIC and then go quickly (less than two inches worth of distance) to the connectors. Moving cables, separating leads, etc. does not influence the picture. It happens on the board and /only/ when C is connected too. Strange.. With NTSC, CHROMA on the NTSC seems to be much more blurry and maybe that's the reason NTSC does not exhibit this.. -- SD! Message was sent through the cbm-hackers mailing listReceived on 2013-05-05 10:00:20
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