Name: CTWOS Type: Variable Category: Drawing pixels
Cassette, Flight, Docked, 6502SP
ElectronSummary: Ready-made single-pixel character row bytes for mode 5 Deep dive: Drawing colour pixels in mode 5Summary: Ready-made double-pixel character row bytes for the mode 4 dashboard
Cassette, Flight, Docked
ElectronReady-made bytes for plotting one-pixel points in mode 5 (the bottom part of the split screen). See the dashboard routines SCAN, DIL2 and CPIX2 for details.This table is not used by the 6502 Second Processor version of Elite. Instead, the CTWOS table in the I/O processor code is used, which contains single-pixel character row bytes for the mode 2 dashboard.Ready-made bytes for plotting two-pixel points in the mode 4 dashboard (the bottom part of the screen). The layout of the pixels is similar to the layout of four-colour mode 5 pixels, so the byte at position X contains a 2-pixel mode 4 dot at position 2 * X (we do this so the same code can be used to create both the monochrome Electron dashboard and the four-colour mode 5 dashboard in the other versions).
Cassette, Flight, 6502SPThere is one extra row to support the use of CTWOS+1,X indexing in the CPIX2 routine. The extra row is a repeat of the first row, and saves us from having to work out whether CTWOS+1+X needs to be wrapped around when drawing a two-pixel dash that crosses from one character block into another. See CPIX2 for more details.
Cassette, Flight, 6502SP
ElectronEQUB %10001000 EQUB %01000100 EQUB %00100010 EQUB %00010001 EQUB %10001000EQUB %10001000 EQUB %01000100 EQUB %00100010 EQUB %00010001EQUB %11000000 EQUB %00110000 EQUB %00001100 EQUB %00000011