Video DAC

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Revision as of 20:45, 14 November 2021 by Jeffythedragonslayer (talk | contribs) (added pinout)
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The video DAC is connected to the RCP over a video bus. The Video Interface (VI) sends data to the video DAC from the framebuffer. The video bus is one (7-bit) byte wide and also has a !DSYNC signal. The !DSYNC signal is active on the first out of four bytes. The bus comes out of the RCP and is fed into the video DAC. A clock signal (about 50Mhz) is also connected to the DAC. Only NTSC supports s-video. The control deck can be modified to suport RGB as this was left unconnected in the retail.

Pinout:

 ----------          --------
|          |        |        |
|        D0|--------|        | composite video
|        D1|--------|        |----------------
|        D2|--------|        |
|  RCP   D3|--------|  DAC   | luma (s-video)
|        D4|--------|        |----------------
|        D5|--------|        |
|        D6|--------|        | chroma (s-video)
|    !DSYNC|--------|        |----------------
|     clock|---+----|        |
|          |   |    |        |
 ----------    |     --------
               |
              OSC (~50Mhz)