Display Peripheral - MARIE-js/MARIE.js GitHub Wiki

MARIE.js has a 15-bit RGB 16x16 display as an output device, which can be accessed by clicking on "Display" tab on the right side. This allows you to draw pixels to screen using assembly code.

The display reads from the last 256 memory cells, that is between addresses 0xF00 and 0xFFF inclusive.

Memory address	Row number	Column number
0xF00	1	1
0xF01	1	2
...	...	...
0xF0F	1	16
0xF10	2	1
0xF11	2	2
...	...	...
0xF1F	2	16
...	...	...
...	...	...
0xFFF	16	16

Each memory cell reads 5 bits for each colour channel, with the most significant bit unused.

Unused	Red	Green	Blue
1 bit (most significant bit)	5 bits	5 bits	5 bits (least significant bits)

This feature is to help explain memory-mapped I/O, which is one of two ways to connect between CPU and peripheral device.