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Cards In This Set
| Front | Back |
 What Does MAR stand and what does it do? |
 It is called memory address register its goal is to hold a memory address |
 What does IR Stand for and what does it do |
 It stands for instructive register. It holds an instruction code |
 What does AC stand for and what does it do? |
 It stands for accumulator it is a general purpose register |
 What does DR stand for and what does it do? |
 It stands for Data register. It holds data |
 What are the three basic fields of instructions |
 1. opcode, 2. address field, 3. mode field |
 What does opcode do |
 The goal is Specifies the operation to be performed. # of bis of this field may determine the # of operation types |
 What does Address field do? |
 Specifies, usually a memory address.
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 What is mode field |
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 What are the three instructional groups based on accesed components |
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 What does memory reference instructions do |
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What does register reference |
 It refers to register instructions it access registers in the cpand it assigns opcode 111 with I-lit=0 |
 What does I/O do |
 To access registers, assign opcode 111 with 5-bit= 1 |
 Mememory-reference instruction consist of assembly code what are the instruction |
 1. AND 0002. ADD 0013. Load 0104. Store 0115. 0xxx add direct6 1xxx add direct |
 The CLA instruction does what |
 It clears ac 7800 (4 hex digit) i. 7=0111, 8=1000, 0=0000, 0=0000 |
 The CMA instruction does what |
 It compliments AC-7200 |
