[Coco] Syscall to get the window screen and width

[Patrick Ulland]

On 3/8/2025 9:28 AM, plt via Coco wrote:
> In Basic09 is there a way to find the current window that your using?
>
> Thanks

If you are coming from DECB, is this the XY problem starting to gel?


Let me ramble a minute. In Microsoft Basic (DECB), everything is flat - 
if you can write it, you can read it back. This includes the video 
display, everything on it and every register that controls it. Example, 
it makes sense to save game state as/on the display to save total 
address space.


In OS9, the screen is conceptually output only. It’s RAM is not your 
RAM, yes you can get there at a cost, unless Level 1 forces your hand 
you probably want to make your own screen with dwset or owset and work 
with that. Keep in mind the screen is outside your 64K, it is simply the 
output device/resolution for this run.


Once you write things to it, those things are gone. Can’t quickly PEEK a 
pixel color for hit detection, etc. Instead we must use a local fixed 
size array that is inside your 64k. Work in that space, then as output, 
project to that variable sized external screen.


It’s worth the trip.

-ricku