Which of the following addresses a portion of the primary memory by specifying the actual address of the memory location? 

Answer options:

A. direct addressing
B. Indirect addressing
C. implied addressing
D. indexed addressing

A

Absolute/Direct - +------+-----+--------------------------------------+ | load | reg |address | +------+-----+--------------------------------------+ (Effective address = address as given in instruction) This requires space in an instruction for quite a large address. It is often available on CISC machines which have variable-length instructions, such as x86. Some RISC machines have a special Load Upper Literal instruction which places a 16-bit constant in the top half of a register. An OR literal instruction can be used to insert a 16-bit constant in the lower half of that register, so that a full 32-bit address can then be used via the register-indirect addressing mode, which itself is provided as "base-plus-offset" with an offset of 0. http://en.wikipedia.org/wiki/Addressing_mode(Very good coverage of the subject) also see: Source: KRUTZ, Ronald L. & VINES, Russel
D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, page 186. also see: http://www.comsci.us/ic/notes/am.html