Ben + UBB + a few components = "VGA"

Werner Almesberger werner at
Sun Apr 24 02:13:35 EDT 2011

This is what it does:

(This shows the Jlime desktop. The friendly gentleman in the background
image may be the Muffinman.)

This is what it looks like:

And here is how it works:

The "VGA" is if course a li^W^Wmarketing. The horizontal resolution is
nowhere near real VGA (it's equivalent to 160-320 pixels), but the
timing is almost correct.

Color depth is one bit per color. I used all but one signal, so one
could add one more bit to, say, green. One could probably free another
bit by multiplexing HSync and VSync.

The program does a number of evil things, including the disabling of
interrupts and the display refresh, to gain memory bandwidth and to
have more predictable timing.

- Werner

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