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Version analysis of TWOS

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

Code variations between these versions are shown below.

Name: TWOS Type: Variable Category: Drawing pixels Summary: Ready-made single-pixel character row bytes for mode 4 Deep dive: Drawing monochrome pixels in mode 4

Code variation 1 of 2A variation in the comments only

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Ready-made bytes for plotting one-pixel points in mode 4 (the top part of the split screen). See the PIXEL routine for details.
This table is not used by the 6502 Second Processor version of Elite. Instead, the TWOS table in the I/O processor code is used, which contains single-pixel character row bytes for the mode 1 screen.
.TWOS EQUB %10000000 EQUB %01000000 EQUB %00100000 EQUB %00010000 EQUB %00001000 EQUB %00000100 EQUB %00000010 EQUB %00000001

Code variation 2 of 2Specific to an individual platform

This variation is blank in the Cassette, Disc (flight), Disc (docked) and 6502 Second Processor versions.

EQUB %10000000 EQUB %01000000