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Elite on the BBC Micro

Save and load: CHK2 [6502SP version]

Name: CHK2 [Show more] Type: Variable Category: Save and load Summary: Second checksum byte for the saved commander data file Deep dive: Commander save files The competition code
Context: See this variable in context in the source code Variations: See code variations for this variable in the different versions References: This variable is used as follows: * DFAULT calls CHK2 * SVE calls CHK2

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 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