Tree challenge description
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Assembling the code:

The assembler file is provided in BeebAsm format, to be assembled on a PC. This generates the 6502 code and adds it to a BBC Micro DFS disc image (image filename tree.ssd). The actual file on the disc is simply called TREE.

To run it, insert disc image into an emulator and type *TREE.

How it works:

To minimise executable size the code takes a parameter which is the width of the first row of each section of the tree. It then draws 4 lines, starting with the given width. The growth rate is computed automatically based on the starting width.

If the starting width is zero it draws two rows of width 3.

Each row is centred on a 40 column screen.

