Re: Save file check sums

Yeah, working with save files should be interesting.

Hopefully pgm checksums aren't much more difficult.

Thanks again.


----- Original Message ----- 
From: <Gene_Gaunt@xxxxxxxxxxxxxxx>
To: "MI Programming on the AS400 / iSeries" <mi400@xxxxxxxxxxxx>
Sent: Thursday, November 06, 2003 8:15 AM
Subject: Re: [MI400] Save file check sums


>
> Foiling CPF5175 eh?  This is the first algorithm.  The second algorithm on
> RISC requires a 2048-byte substitution table.
>
> 01. initialize a 68-byte workarea to binary zeros
> 02. at workarea pos 8: copy savefilerec pos 1-57 & 513-516 (61 bytes)
> 03. shift workarea one bit left
> 04. at workarea pos 7: ADDLC savefilerec pos 58-119 (62 bytes)
> 05. shift workarea one bit left
> 06. at workarea pos 6: ADDLC savefilerec pos 120-182 (63 bytes)
> 07. shift workarea one bit left
> 08. at workarea pos 5: ADDLC savefilerec pos 183-246 (64 bytes)
> 09. shift workarea one bit left
> 10. at workarea pos 4: ADDLC savefilerec pos 247-311 (65 bytes)
> 11. shift workarea one bit left
> 12. at workarea pos 3: ADDLC savefilerec pos 312-377 (66 bytes)
> 13. shift workarea one bit left
> 14. at workarea pos 2: ADDLC savefilerec pos 446-512 (67 bytes)
> 15. shift workarea one bit left
> 16. at workarea pos 1: ADDLC savefilerec pos 378-445 (68 bytes)
> 17. initialize checksum (savefilerec pos 517-528) to binary zeros
> 18. at savefilerec pos 524: copy workarea pos 1-5 (5 bytes)
> 19. shift checksum one bit left
> 20. at savefilerec pos 523: ADDLC workarea pos 6-11 (6 bytes)
> 21. shift checksum one bit left
> 22. at savefilerec pos 522: ADDLC workarea pos 12-18 (7 bytes)
> 23. shift checksum one bit left
> 24. at savefilerec pos 521: ADDLC workarea pos 19-26 (8 bytes)
> 25. shift checksum one bit left
> 26. at savefilerec pos 520: ADDLC workarea pos 27-35 (9 bytes)
> 27. shift checksum one bit left
> 28. at savefilerec pos 519: ADDLC workarea pos 36-45 (10 bytes)
> 29. shift checksum one bit left
> 30. at savefilerec pos 518: ADDLC workarea pos 58-68 (11 bytes)
> 31. shift checksum one bit left
> 32. at savefilerec pos 517: ADDLC workarea pos 46-57 (12 bytes)
> 33. at savefilerec pos 517: XOR first record's timestamp (8 bytes)
>
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