On 02/03/2013 05:41 PM, Rob Clarke wrote: > > I then thought maybe something in the modulator was holding it low so I > bent the pin out of the socket but it remains firmly low. The luma pin needs a pullup to work. It will only sink current but not supply it. The datasheet specifies a 500 Ohm pullup. The usual circuit also contains a diode (1N4148 for example) between VIC and pullup. > What is the minimum requirements a VIC-II needs to generate a sync > signal? It should do that once you supply power and clock. There will be no picture, but the sync signals should be there. Can be easily seen if you use a real CRT monitor. When you turn on an otherwise dead C64, you still get a twitch from the monitor once it locks onto the sync signal from VIC. Also, on the 250425: - +12V are present at Pin13 of the VIC? - Clock signals are present (dot clock and color clock!)? - Does the board contain any MOS-TTLs? (small ICs with MOS logo and a 77xx number) - Modulator has power? Even if you use the video out, the modulator is needed to convert the video signals into Y/C and CVBS. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2013-02-03 19:00:04
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