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Elite on the BBC Micro

Version analysis of CHK2

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

Code variations between these versions are shown below.

Name: CHK2 Type: Variable Category: Save and load Summary: Second checksum byte for the saved commander data file Deep dive: Commander save files The competition code
Second commander checksum byte. If the default commander is changed, a new checksum will be calculated and inserted by the elite-checksum.py script. The offset of this byte within a saved commander file is also shown (it's at byte #74).
.CHK2

Code variation 1 of 1Related to the 6502SP version

The Executive version contains a maxed-out default commander, which has a different second checksum byte.

Tap on a version to expand it, and tap it again to show to all variations.

Cassette, Flight, Electron

Master

6502SP

EQUB &03 EOR &A9 \ The checksum value for the default commander, EOR'd \ with &A9 to make it harder to tamper with the checksum \ byte, #74
EQUB 0
IF _SNG45 OR _SOURCE_DISC EQUB &03 EOR &A9 \ The checksum value for the default commander, EOR'd \ with &A9 to make it harder to tamper with the checksum \ byte, #74 ELIF _EXECUTIVE EQUB &3F EOR &A9 \ The checksum value for the maxed-out default \ commander, EOR'd with &A9 to make it harder to tamper \ with the checksum byte, #74 ENDIF
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