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⌂ ∞ ▽ Elite on the 6502

Version analysis of DL

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

Code variations between these versions are shown below.

.DL

Code variation 1 of 1Specific to an individual platform

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Cassette, Flight, Docked, 6502SP, Master
Electron
 SKIP 1                 \ Vertical sync flag
                        \
                        \ DL gets set to 30 every time we reach vertical sync on
                        \ the video system, which happens 50 times a second
                        \ (50Hz). The WSCAN routine uses this to pause until the
                        \ vertical sync, by setting DL to 0 and then monitoring
                        \ its value until it changes to 30

 SKIP 1                 \ This byte is unused in this version of Elite (it is
                        \ used to store the vertical sync flag in the BBC Micro
                        \ versions)