Version analysis of ALTIT - Elite on the 6502

This code appears in the following versions (click to see it in the source code):

Cassette, Disc (flight), Disc (docked), 6502 Second Processor, Master and Electron

Code variations between these versions are shown below.

.ALTIT

Code variation 1 of 2A variation in the comments only

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Cassette, Flight, Docked, 6502SP, Master
Electron
 SKIP 1                 \ Our altitude above the surface of the planet or sun
 SKIP 1                 \ Our altitude above the surface of the planet

                        \
                        \   * 255 = we are a long way above the surface
                        \
                        \   * 1-254 = our altitude as the square root of:
                        \
                        \       x_hi^2 + y_hi^2 + z_hi^2 - 6^2
                        \
                        \     where our ship is at the origin, the centre of the

Code variation 2 of 2A variation in the comments only

Tap on a block to expand it, and tap it again to revert.

Cassette, Flight, Docked, 6502SP, Master
Electron
                        \     planet/sun is at (x_hi, y_hi, z_hi), and the
                        \     radius of the planet/sun is 6
                        \     planet is at (x_hi, y_hi, z_hi), and the radius
                        \     of the planet is 6

                        \
                        \   * 0 = we have crashed into the surface