[Arm-netbook] libre hardware

[Christopher Havel]

@ Mr Afzal -- I designed a relatively insignificant portion of the video
circuitry. It appears on the Micro-Desktop PCB. I consider it a bit of a
kludge -- it's effective, but only by brute force. It's hobbyist grade
stuff... then again, I'm a hobbyist, so I suppose it's to be expected...

90% of it was taken straight from Wikipedia's article on the subject; all I
did was calculate values for some passives and IIRC provide a way of
turning part of it off.

Basically it's a DAC -- digital to analog converter. It converts the
TTL-level (0-5v) pulses off the CPU card to the 0-0.7v analog voltages
required for the RGB lines on the VGA port. It's the cheap and nasty R-2R
resistor ladder kind of DAC. Sure, it's inexpensive, but it'd give any real
electronics engineer a cringe and a shudder. Dave Jones (EEVBlog on
YouTube) would quite likely pop a gasket if he saw such a job in *anything*
professional, and quite honestly I somewhat agree with him. I want to say
the ability to switch between 16bit and 24bit color was done with a couple
of 74xx logic chips, but I don't remember offhand which ones I used.
(Forgive me, it's been a couple years.)

The honest truth is that the triple-fistful of passives in there *should*
be replaced by a trio of dedicated flash-DAC chips -- far less crude and
far more effective.

I'm proud of the work in an "I contributed to a cool thing" sort of way,
but that's really the only way I'm proud of it. It's not something to be
proud of in terms of design, that's for sure...
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