[Oberon] FPGA - Colour Support

Tomas Kral thomas.kral at email.cz
Mon Oct 16 10:47:17 CEST 2017

On Mon, 16 Oct 2017 09:23:20 +0100
Paul Reed <paulreed at paddedcell.com> wrote:

> Part of the stated goal of Project Oberon is to show how much you can
> do with

I can do bitmaps and pictures here within 1MB of SRAM on PO2013
reference platform (pictures fund on Alto,Ceres systems). I believe I
can also do 8/16 colours in 1MB for smaller objects, but agree 2MB
could be better.

I currently seek help in defining `stacked 1bit planes'.

My idea is to keep `Display.Mod' unchanged, add `Display1.Mod' to define
colours, and later `Display3.Mod' with drawing primitives.

Most of the time we will write only to B&W bit plane anyway, as PO2013
is not web browser nor DTP system.

1bit planes idea>>>

(* display buffer addresses *)
bw_plane := ... 
red_plane := bw_plane + sizeof (bw_plane)
green_plane := bw_plane + 2 * sizeof (bw_plane)
blue_plane := bw_plane + 3 * sizeof (bw_plane)

SYSTEM.PUT(bw_plane, 1) (* sets pixel on/off *)
SYSTEM.PUT(red_plane, 1) (* sets the same pixel red *) OR
SYSTEM.PUT(green_plane, 1) (* sets the same pixel green *) OR
SYSTEM.PUT(blue_plane, 1) (* sets the same pixel blue *) 

Tomas Kral <thomas.kral at email.cz>

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