The 4bit instruction is placed per default to the msb (most significant bits) in the command

00 60 ORC    RR       Set RR to 1
01 A0 IEN    RR       Enable inputs
02 B0 OEN    RR       Enable outputs

Calling the assembler with the -i (or --ilsb) option or putting

OPT ILSB

to the assembly file moves the instruction to the lsb (least significant bits) in the command

00 06 ORC    RR       Set RR to 1
01 0A IEN    RR       Enable inputs
02 0B OEN    RR       Enable outputs