Another alphanumeric code was developed in the 1970s. It is known by names such as Code...

Another alphanumeric code was developed in the 1970s. It is known by names such as Code 39 and Code 3 of 9. It is a variable-length code that has been used by the Department of Defense, in nonretail and industrial applications, in warehouse and inventory management, and in the pharmaceutical industry. The code uses the digits 0 through 9, the uppercase letters of the alphabet, and several symbols. A check digit is not required, but when a check digit is included, the code uses a mod 43 check-digit scheme on the sum of the character values and the check digit is the last character in the identification number. In order to calculate the check digit, each character must be assigned a value according to the following table. Notice that some punctuation symbols are significant in this coding system.

a. Assuming a check digit has been used, is 2A-482TWZ a valid Code 39 identification number?

b. For a Code 39 identification number SP245399MX65, find the check digit.