Re: Mod 10 check digit calculation

[Wayne McAlpine <wayne.mcalpine@xxxxxxxxxxxxxxxxx>]

The DDS Reference manual for display files contains detailed 
instructions on how to calculate both mod10 and mod 11 check digits.  Go 
to the Information Center to view it.

Douglas Handy wrote:
> Michael,
>
> You want a mod 10 calculation of a number right?
>
> Am I missing something?
>
>
> Yes, you are missing the fact he isn't referring to a mathematical modulus
> operation, but instead is referring to the check digit computation algorithm
> (especially popular in keypunch days) where the final digit is computed off
> the preceding digits.  Conceptually similar to bar code or credit card check
> digits, it aids in detecting common keying errors like transposed digits.
> The two common methods were referred to as Mod 10 and Mod 11, and you could
> have keypunch machines or even 5250 terminals perform the check as the data
> was keyed.  See DDS keyword CHECK() values such as M10 and M11.
>
> Doug