[Oberon] System-V - Frame Clipping

[Tomas Kral]

> VAR F: Display.Frame
> Clip(F) (*clipping ON*)
> Clip(NIL) (*clipping OFF*)

RISC-5 has some reserved address space from $FFFF00 to $FFFFFF, some
used by H/W mapped registers for I/O.

I was thinking, to use some of those for `VID.v' clipping.

Procedure `Clip()' would fiddle with some of these reserved addresses.

Is it worthwhile, or
just bad idea, difficult, complex or costing many cycles, and
stalling CPU?

-- 
Tomas Kral <thomas.kral at email.cz>