MICR Commands and Parsing

In this example, without an exception table entry, the firmware would not be able to pick out the check serial number because it is not separated from the rest of the account number:

txxxxxxxxxt ccccxxxxxxxxxxo

In this example, without an exception table entry, the firmware would not be able to pick out the check serial number correctly, because it is imbedded within the rest of the account number:

txxxxxxxxxt xxx-ccc-xxxxxxxxxxo

Loading the Exception Table

The exception table begins at word 20 in NVRAM. Each entry takes five words. There is room for eight exceptions with a sumcheck written in the last word. An application can load local exceptions into the printer using the write NVRAM command:

0x1B 0x73 n1 n2 k

which writes the two byte word n1:n2 to word k in NVRAM.

Exception Table Entry Format

Each exception table entry consists of five words. The first two words contain the first eight characters of the transit number by packing the low order nibble of the numeric transit number characters. For Canadian checks, eliminate the dash and store the eight numerics.

The next three words are used as six individual bytes to tell the firmware how to interpret the MICR characters which fall to the right of the rightmost transit symbol. Each of the six bytes is positional and consists of two parts: character type and number.

3255 4073–002

11–11

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Unisys EFP9800 manual Exception Table Entry Format, Loading the Exception Table