Block Recusion Idea in OZLOGO
The Block Recursion Fractal Concept in OZ-LOGO

The Screen Robot = NAKI
Block-Recursive Naki

OZ-LOGO is the generic name of a "Tiny"version of LOGO I implemented for the Australian 8-bit microcomputer the MicroBee in 1983. (The microBee was based on the Z-80 8-bit microprocessor). OZ-LOGO was marketed by Applied Technology on a 2K ROM.

The OZ-LOGO Screen Robot (NAKI).

The OZ-LOGO Screen Robot (NAKI) moved about a tiled region on the screens. The tiles were the same size as the naki itself, and there were 16x16 of the tiles in the naki territory (for the basic mode). The naki had just four possible headings, North (upscreen) , South , East and West .
As in traditional line-oriented logo - the NAKI could leave a trail - as it moved from tile to tile. The trail was made up of dump tiles.
The dump tiles used for trail-marking were created as the thumb image of the naki territory, if a cell in the territory was marked, then the corresponding pixel in the thumb was set. Of course, a tile could be exploded to full-size, using either a standard black tile, or the current dump character.


Note that in the naki-recursive naki, each block of the naki is similar to the whole. More generally, for block-oriented fractals, each block of the fractal is similar to a larger block of the image. This more general class of block-oriented fractals was available in OZ-LOGO for the 16x16 mode. In sum. OZ-LOGO was the first demonstration of the concept of block-oriented self-similarity, the basis for fractal image coding.


E.Jacquin, A novel fractal block-coding technique for digital images, IEEE Trans. Image Processing, 1992, Vol 1, No 1, pp 18-30.