Return Codes from TRKCALC

The TRKCALC macro passes a return code in register 15. The return codes and their meanings are as follows:

Return Code	Meaning
0 (X'00')	Indicates that register 0 contains the new track balance.
4 (X'04')	Indicates that the record did not fit (register 0 = 0).
8 (X'08')	Indicates that the record did not fit. (Register 0 contains the maximum data length that does fit.)
12 (X'0C')	The system could not find an entry in the device characteristics table whose attributes match those of the user-specified device type. Register 0 is set to zero.