[Arm-netbook] Question about resolution on the micro-desktop

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Fri, Jan 13, 2017 at 6:56 PM, Benson Mitchell
<benson.mitchell+arm-netbook at gmail.com> wrote:
> On Jan 13, 2017 12:31 PM, "dumblob" <dumblob at gmail.com> wrote:
>
> Hi Luke,
>
>>
>> in the
>> case of fixed LCDs, the only way to guarantee that is to have line (or
>> frame) buffer upscaler ICs *ON THE HOUSING*.
>
>
> I think there was another discussed solution not requiring "anything" (not
> even line buffer upscaler IC) on the housing. Namely just drawing the small
> resolution directly to the higher-resolution display to the edge where the
> signal starts drawing the first line).
>
>
> Seems to me it's not that simple -- displays not only require a specific
> resolution, but a specific timing. To display a 1366x768 output unscaled on
> a 1920x1080 display requires one of two things:
> (1) Compatible timings -- the 1366x768 output must have the same horizontal,
> vertical, and pixel frequencies as the 1920x1080 display expects. In
> essence, the "1366x768" signal is *identical* to a 1920x1080 signal, with
> black bars on some or all edges.
> (2) Rescaling hardware -- in general, this means a full frame buffer,
> whether the vertical frequencies match or not. In specific cases where the
> vertical frequencies and the horizontal frequencies match, you can use a
> single line buffer. For example, displaying a 960x1080 at 60Hz screen on half
> of a 1920x1080 at 60Hz screen.

 ohhh that explains why chrontel do both line buffer and frame buffer
scaling ICs.

> (Obviously, if you've got a third approach, do tell us!)

 i haven't!

 hmmm.... y'know... i believe it reasonable to assume that the output
hardware is sufficiently flexible to be able to arbitrarily scale the
vertical, horizontal, clock frequencies, sync pulses and more.

 heck, even the opencores.org VGA/LCD controller which was borrowed
and used in the ICubeCorp IC1t is capable of all that.

 i really _really_ appreciate you bringing this up, though, as it's
going to be important to mention in the notes.

l.