An assembler pseudo operation controlling the method of assembly. (See the assembler section for more details). OPT should be followed by a number in the range 0 to 7. The way the assembler functions is controlled by the three bits of this number in the following manner.

Bit 0 - LSB

Bit 0 controls the listing. If it is set, a listing is displayed.

Bit 1

Bit 1 controls the error reporting. If it is set, errors are reported.

Bit 2

Bit 2 controls where the assembled code is placed. If bit 2 is set, code is placed in memory starting at the address specified by O%. However, the program counter (P%) is still used by the assembler for calculating the instruction addresses.