Dilwyn Jones wrote:
> The designers should add a proper method of detection or explain how
> it can RELIABLY be detected.
> At the moment, the best you can do is look for an identifying string,
> which does nothing other than show it's a version able to support GD2,
> even if GD2 is not possible on the system.

First of all there seems to be some confusion what GD2 actually is.
GD2 is an interface definition, nothing more, nothing less. It
introduced new TRAPs etc. If you check for GD2, you check whether
these TRAPs are available, NOT whether any high colours modes are
supported.
How can you check for GD2? Easy, call IOP.PINF and check the "PTR_GEN"
version. I suggest to demand version 2.0 at least.

Next problem, which modes are available. There I say

"Thou shalt not write applications that alter the colour depth."

But I know that my opinion will get ignored anyway, even though I'll
be the first that gets bothered if something that I said not to do in
the first place does not work or causes problems.

It is true there is no legal way on getting to know which modes are
available, although this information is of course available in the CON
variables. But then I don't want people to rely on those, in case that
some restructuring is needed in the future. We could however introduce
a new CON vector for this purpose.

>> In the absence of comments from Jochen / Marcel I think the
>> problemis that WMAN is reporting that GD2 is available.

Even more mixed up. WMAN is a separate module and although it
currently relies on GD2 it is not the place to ask whether GD2 is
available.

>> Guess the only way of doing this is to try and use one of the new
>> commands added by the device drivers to set the ink / paper etc...

Non starter. Then you still only know whether GD2 is there, but not
whether high colour modes are supported.

One more thing:

> Just spotted a slight problem - does anyone remember the System
> toolkit? That added some extra commands, including TRAP #3, D0=$50
> to read file attributes (such as read only). Let's hope there's no
> software that uses this as it is IOW.papp on colour drivers (set
> paper to system palette)!!

This is no problem. At least if you're not trying to get the file
attributes of a CON/SCR channel, which I think would be pretty
pointless.

Marcel

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