D6Smit00.dat Checksum

[Shadow Stranger]

The small file D6Smit00.dat generates the inventory of the Valeia Armory. It is created every time that a save game is loaded, hence it is created from a part of the save. If you can successfully edit this file at will you can basically create a W&W item editor. You may be able to hit Ctrl + Alt + Delete in the middle of a game, and edit the file. Or you may be able to locate the contents of the file in the save game file itself.
(If you download save 2 from John Hubbard's site, it does not occur?! But if you enter Valeia and go to the armory, it then occurs at around place 662,588 in a file that is 681,846 bytes.)

So far, so good but it is protected by a checksum!
Does anyone know how to compute the checksum for this file? It seems to be CA 1F 0 80.

The number of zeroes, empty places, seems not to affect the checksum. (Below, the first four columns give the item number in hexadecimal, the next four give the quantity stocked by this shop.)

A7 2 0 0 0F 0 0 0
18 0 0 0 3 0 0 0
0A 0 0 0 7 0 0 0
5C 0 0 0 1 0 0 0
19 0 0 0 2 0 0 0
0B 0 0 0 3 0 0 0
1A 0 0 0 4 0 0 0
6B 0 0 0 2 0 0 0
10 0 0 0 3 0 0 0
A9 1 0 0 5 0 0 0
1B 0 0 0 4 0 0 0
2E 2 0 0 1 0 0 0
5 0 0 0 0A 0 0 0
2D 2 0 0 5 0 0 0
29 0 0 0 63 0 0 0
2A 0 0 0 63 0 0 0
2B 0 0 0 63 0 0 0
56 2 0 0 0C 0 0 0
1C 0 0 0 3 0 0 0
1D 0 0 0 3 0 0 0
1E 0 0 0 3 0 0 0
1F 0 0 0 2 0 0 0
20 0 0 0 2 0 0 0
24 0 0 0 1 0 0 0
27 0 0 0 1 0 0 0
96 0 0 0 6 0 0 0
3E 0 0 0 3 0 0 0
3F 0 0 0 1 0 0 0
98 0 0 0 1 0 0 0
19 2 0 0 2 0 0 0
AF 0 0 0 4 0 0 0
61 0 0 0 1 0 0 0
3C 1 0 0 63 0 0 0
0C 3 0 0 2 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0