Saturday, March 12, 2011

Vsync detector chip installed (and working!)

I've installed by LM1881 chip which is designed to detect vsync signals from NTSC/PAL sources. This is important for my VLDP-HW project because a laserdisc player replacement may need to know when vsync occurs in order to be accurate and reliable. (some laserdisc games will not care but some probably will and it's better to be accurate than sorry)

The plan is that the NTSC output, which at this time will come from a PC, will be plugged into the VLDP-HW board via RCA cable so that the VLDP-HW can know when vsync is occurring. And then another RCA cable will come out of the VLDP-HW board and go into the arcade game's NTSC decoder card.

Many thanks to my friend, Warren, who came up with the idea to use this chip and to do the pass-thru scheme. He's helped me a lot on this project :)

Here's a movie of the vsync chip in action (it works!!). WARNING: Movie is 7 minutes long and your eyes may glaze over! :)

Here's the pass-thru cable installed:

Here's me pointing my camera at a TV and taking a picture (infinite loop). This shows that the pass-thru cable is working.

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