Re: Apple][VGA - finally available

[mdj <mdj.mdj@gmail.com>]

On Jul 17, 2:45 pm, Mark McDougall <msmcd...@no.spam.iinet> wrote:

> Personally, I prefer the bus snooping approach because of the
> "(dis)advantage of extreme versatility". Granted, it's more work and perhaps
> even impossible to get *exactly* right, but I believe it's very doable and
> would produce acceptable results for most users who want a comparable
> viewing experience in each video mode, but can't justify the space or
> expense of a dedicated Apple II monitor.

Doable or not, it's using the proverbial sledgehammer to squash the
fly :-)

You can't get any information from the snooping approach that you
can't get more easily from the existing video hardware. Granted, the
only (easily) accessible point on the IIgs for the video signals is
the video port so there's an aesthetic argument for finding another
way. That falls apart when faced with the prospect of reimplementing
the *entire* IIgs video subsystem plus conversion when you can get
away with just conversion.

However, if we're going to go down the aesthetics path, there's an
argument that the existing IIgs renditions of older Apple II video
modes is only passable at best. From that perspective, re-implementing
the original Apple II video subsystem and converting that might
provide more pleasing results. As far as the SHR modes go, re-
implementation isn't going to provide any improvement over upsampling
the existing signal. It is after all only 12 bit RGB; a poor-mans ADC
can handle that with no quality drop and considerably less complex
circuitry.

When it comes to considering extended modes, I'm surprised nobody has
considered the "unsquareness" of Apple II pixels and the impact this
has on the existing software base. It's fun to play "what if", but
most IIgs software designed around 640x200 is going to look rather odd
at 640x480.

As is always the case, there are itches and there are scratchers. Our
community is diverse but small, and unfortunately you need both to
occur in the same person in order to see a solution materialise, and
the probability of this happening is, alas, relatively low.

Matt