$11 checksum

[vn5000]

Does anyone know how to calculate $11 checksum properly .Apparently you have to subtract 6000 -6006 checksum from main checksum 5000 - ffff . Is this correct and is their an easy way to do it besides AA.

[vn5000]

IF anyones interested , to get proper checksum on $11 BLCC bin after editing ,you save file and let tunerpro calculate checksum ,then with a hex editor manually subtract 1253 decimal from tunerpro calculated decimal checksum and all is fine.
1253 is obtained by putting std blcc bin in tunerpro and using tunerpro save file with updated checksum .Then subtract original checksum from tunerpro calculated checksum and this gives you 1253 decimal.

[Doctor Bob]

this will only work for that bin.
the correct method is as you describe in your first post