VMS Help MACRO, VAX MACRO Assembler, Instructions, EDITPC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Edit Packed to Character String
    Format:         opcode srclen.rw,srcaddr.ab,pattern.ab,dstaddr.ab
    Operation:
    C. Codes:       N = {src string} LSS 0; !N <- 0 if src is -0
                    Z = {src string} EQL 0; C = {significance}
                    V = {decimal overflow}; !nonzero digits lost
    Exceptions:     reserved operand, decimal overflow
    Opcode:         38  EDITPC  Edit Packed to Character String
    Description:    The destination string specified by the pattern and
                    destination address operands is replaced by the edited
                    version of the source string specified by the source
                    length and source address operands. The editing is
                    performed according to the pattern string, starting at
                    the address pattern and extending until a pattern end
                    pattern operator (EO$END) is encountered.

                    The pattern string consists of 1-byte pattern operators.
                    Some pattern operators take no operands. Some take a
                    repeat count that is contained in the rightmost nibble
                    of the pattern operator itself. The rest take a 1-byte
                    operand that immediately follows the pattern operator.
                    This operand is either an unsigned integer length or
                    a byte character.
    Notes:          After execution:

                    R0 = length of source string
                    R1 = address of the byte containing the
                         most-significant digit of the source string
                    R2 = 0
                    R3 = address of the byte containing the EO$END
                         pattern operator
                    R4 = 0
                    R5 = address of one byte beyond the last byte of
                         teh destination string