ray@micomvax.UUCP (Ray Dunn) (09/30/88)
Offset 12H of the header of an EXE file contains a 16bit checksum of the EXE file, so that the 16bit sum of the 16bit words of the file including the checksum word is FFFFH. What standard (or other) software checks this sum? What will fail if the sum is wrong? Executing the file doesn't, EXEPACK'ing the file doesn't. In fact EXEPACK sets the checksum to 2B15H, irrespective of its "correct" value. Anyone know why? It doesn't seem to use this as a flag to say that the file is packed, 'cos it still knows that when you change the checksum to an arbitrary value. EXEPACK also seems to embed the message "Packed file is corrupt" in the packed EXE file. What checks cause this to get displayed? If the answer is RTFM, then please say which FM! Thanks. -- Ray Dunn. | UUCP: ..!philabs!micomvax!ray Philips Electronics Ltd. | TEL : (514) 744-8200 Ext: 2347 600 Dr Frederik Philips Blvd | FAX : (514) 744-6455 St Laurent. Quebec. H4M 2S9 | TLX : 05-824090