Usually, all you do is zero an n bit summation variable then add to it each 8 bit entity. Treat as unsigned. Ignore roll-over beyond 2^n. That's it. Doesn't detect errors such as a whole character of zeros lost, or complementary errors. ---------- From: Jim Main[SMTP:jmain@CQM.CO.UK] Sent: Friday, March 15, 1996 4:36 PM To: Multiple recipients of list PICLIST Subject: Checksumming I need to attach checksums to strings outgoing, and check checksums attached to strings received. The checksum being the sum of all the data '1' s in the bytes of the string. Is there an easy way to do this?? Jim M`P`.````S <#``\`%0`0`#0`!0!#`0$@@ ,`#@```,P'`P`/`!4`#@`I``4` M-@$!"8 !`"$````P-T$Y1#(X-T$T-T5#1C$Q.30U030T-#4U,S4T,# P, #G M!@$#D 8`4 0``!(````+`",```````,`)@``````"P`I```````#`#8````` M`$ `.0! V6G)]Q*[`1X`< `!````$0```%)%.B!#:&5C:W-U;6UI;F<````` M`@%Q``$````6`````;L2]\EIA]*I"'ZD$<^46D1%4U0`````'@`># $````% M````4TU44 `````>`!\,`0```! ```!S=&5V96- )S=&5M`H,S=P+D!Q,"@'T*@ C/"=D[\18/ M,C4U`H *@0VQ"V#@;F@209QP0`Y$#H&)I!4 ;`&W)`,!T:0(@('8*P ;B#1.1& ="<$ M(!T0(-!$;[D'D&XG!4 -L!/08Q^A/G(#8!&@'3$?X2%182#T=V@&\&4*A1%R M`- 3T/D%P&]F'%,$(!6@$\ ;8'L%L06@;0M0$^ @<0K >0TEY2X*A0J+;&DQ M.((P`M%I+3$T- WPYPS0++,+63$V"J #8"6COBTNUPJ'+8L,,"Y61@-ASCHO MWBY6#((@2@=P!= !"W%;4TU44#IJ`P# "X! 0U%-+D/@3RY52UTO?S"-!F"/ M`C QOS++,7!I9&$;424ST'(?X3$U&V Q.4 Y-B T.C,ZX%!F335_,(U4;S>_ M,LM-_'5L'9 IL2* !9 %( B0/P(P!" H82P0$\ [0$E#,$Q)4U0[?S:.=6(N M:B6Q/9\RRT,>@&-K^QU""X!G*M\KXSL@+5<:1?TN5DD4$K&(X%&@7\>8ATR*%(;@E(R.< !D"!X)S$G'3 <( .@4C)B MOGD3T$"34C-+HRK-24M!KQZ (F$#D1_ < 0`/S]&O#.1 MOT:\1R](/RYE"H45,0!=X ````,`$! ``````P`1$ ````! ``_<2 DNP% ``@PX*(K>_<2NP$>`#T``0````4```!213H@`````/8U ` end Attachment converted: wonderlandtwo:WINMAIL.DAT (????/----) (0000258D)