Version analysis of TWOS2 - 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 and Electron

Code variations between these versions are shown below.

       Name: TWOS2
       Type: Variable
   Category: Drawing pixels
    Summary: Ready-made double-pixel character row bytes for mode 4
  Deep dive: Drawing monochrome pixels on the BBC Micro

Code variation 1 of 2A variation in the comments only

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Cassette, Flight, Docked, Electron
6502SP
 Ready-made bytes for plotting two-pixel dashes 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 TWOS2 table in the I/O processor code is used, which contains double-pixel
 character row bytes for the mode 1 screen.



.TWOS2

Code variation 2 of 2Related to the screen mode

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

Cassette, Flight, Docked, 6502SP
Electron
 EQUB %11000000
 EQUB %01100000
 EQUB %00110000
 EQUB %00011000
 EQUB %00001100
 EQUB %00000110
 EQUB %00000011
 EQUB %00000011
 EQUB %11000000
 EQUB %11000000
 EQUB %01100000
 EQUB %00110000
 EQUB %00011000
 EQUB %00001100
 EQUB %00000110
 EQUB %00000011