HP 35s Checksum explained

[Didier Lachieze]

I've tested the small program listed in this thread from 2007: 35s checksum problem

On my real 35s (ROM version 1 - CNA743xxxxx) I have:
LBL G, LN= 9, CK= 535D
LBL C, LN= 9, CK= 532C

On the 35s emulator (Version 2012 12 10 Rev:19048) I have:
LBL G, LN= 9, CK= B556
LBL C, LN= 9, CK= 7C6B

Both real and emulated 35s had already some (different) programs inside before the test. On both I first did GTO .. before entering the program.