[Coco] USRx() and adding more parameters?

[William Astle]

On 2025-11-05 11:13, Sean Conner via Coco wrote:
>    Attached is another proof-of-concept.  This implements a USRn function
> that draws a pattern (8x8, based on early Mac background patterns) on the
> screen in a given area, and cycles through 38 such patterns when you hit a
> key.  It works best in PMODEs 0, 2 or 4.  The critical line is:
> 
> 	110 X=USR0(P),(65,49)-(190,142)
> 
> The first parameter is the pattern #, then a comma, then the upper left
> corner, then the lower right corner of the area to draw the pattern, using
> the code BASIC uses to parse the LINE command.  Looks weird, but it works.

Incidentally, you can do the same "parse extra stuff" thing with EXEC as 
well.