MARIE, a Machine Architecture that is Really Intuitive and Easy, is a simple architecture consisting of memory (to store programs and data) and a CPU (consisting of an ALU and several registers). It has all the functional components necessary to be a real working computer. MARIE will help to illustrate the concepts in this and the preceding three chapters. We describe MARIE’s architecture in the following sections.
MARIE has the following characteristics:
Binary, two’s complement
Stored program, fixed word length
Word (but not byte) addressable
4K words of main memory (this implies 12 bits per address)
16-bit data (words have 16 bits)
16-bit instructions: 4 for the opcode and 12 for the address
A 16-bit ...