Function Name
CRC
Purpose
Compute a checksum for a data region.
Call Address
$C20E
Input
R0 - $02-$03 - Pointer to the data region.
R1 - $04-$05 - Length of the region.
Output
R2 - $06-$07 - Checksum of the region.
Description
This routine is called by the bootup routines to compute the checksum of GEOS BOOT. This checksum is used to create the interrupt vector address. The reason for this was to prevent piracy. This can be used to check the integrity of a memory region. This is actually more of a CRC computation than a checksum, and the formula is a little too complex to explain here.
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