Instruction Set
The PDP-11 operates on bytes and words. Bytes are specified by a register number—identifying the register's low-order byte—or by a memory location. Words are specified by a register number or by the memory location of the low-order byte, which must be an even number. In most instructions that take operands, bit 15 is set to specify byte addressing, or clear to specify word addressing. In the lists in the following two sections, the assembly-language programmer appended B to the instruction symbol to specify a byte operation; for example, MOV became MOVB.
Read more about this topic: PDP-11 Architecture
Famous quotes containing the words instruction and/or set:
“And, fathers, do not provoke your children to anger, but bring them up in the discipline and instruction of the Lord.”
—Bible: New Testament, Ephesians 6:4.
“Well, most men have bound their eyes with one or another handkerchief, and attached themselves to some of these communities of opinion. This conformity makes them not false in a few particulars, authors of a few lies, but false in all particulars. Their every truth is not quite true. Their two is not the real two, their four not the real four; so that every word they say chagrins us and we know not where to set them right.”
—Ralph Waldo Emerson (1803–1882)