Re: DHGR Color Question

[mjmahon@aol.com (Michael J. Mahon)]

Jeff Blakeney replied:

>On 01 Jan 2004 01:26:26 GMT, mjmahon@aol.com (Michael J. Mahon) wrote:
>
>>When in DHGR mode, there are 140 pixels per line, with 16 color
>>possibilities.  The colors are still "artifact" NTSC colors produced
>>by four bits per pixel (two from the main bank and two from the
>>auxilliary bank).
>
>I may be wrong here as it has been a long time since I've done
>anything with DHR graphics but aren't the pixels in colour mode split
>up kind of weird?  If I remember correctly the first pixel's 4 bits
>are all in one bank and the second pixel's 4 bits are split with 3
>bits coming for the first bank and the last bit coming from the second
>bank and so on across the screen.  This is because the 8th bit of each
>byte is not visible (was used for colour shifting in HR graphics but
>does nothing in DHR graphics).  It would look something like this (use
>a mono-spaced font):
>
>Bank   Main     Aux    Main     Aux    Main     Aux    Main     Aux
>Pixel 1111222 2333344 4455556 6667777 8888999 9AAAABB BBCCCCD DDDEEEE

I haven't checked my references, but that looks about right, given
the way the 80-column hardware works.

-michael

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