Re: Asynch comm

["Leif Svalgaard" <leif@xxxxxxxx>]

the XOR function is a fundamental logical function of two bits like this

XOR (0,0) = 0; XOR(1,0) = 1; XOR(0,1) = 1; XOR(1,1) = 0;

so, if the two bits are different XOR is 1, otherwise 0.

You can apply the function on each bit of the character, to

get XOR at the character level. How you do an XOR depends

a bit (no pun intended) on the language you are using.

Check your manuals for it.

----- Original Message -----

From: Jim Franz

To: MIDRANGE-L@midrange.com

Sent: Monday, May 29, 2000 1:50 PM

Subject: Asynch comm

I am working on an AS/400 to a credit card authorization network. Unfortunately no previous AS/400 has previously certified to this network. I'm hoping someone else has seen this requirement for async communications. The specs from the other system call for me to add an LRC code at end of packet, "each record must be immediately followed by an LRC character that is computed by using the XOR function on each character of the record. This is a data integrity check." The network person on the other side is not able to really describe what it is. Sounds like some sort of check digit for the whole packet. Any ideas?

Jim Franz