Instruction Set used in simplified instructional Computer (SIC)

Prerequisite – Simplified Instructional Computer (SIC) 
These are the instructions used in programming the Simplified Instructional Computer(SIC). 

Here, 
A stands for Accumulator 
M stands for Memory 
CC stands for Condition Code 
PC stands for Program Counter 
RMB stands for Right Most Byte 
L stands for Linkage Register 

 

MNEMONIC OPERAND OPCODE EXPLANATION
ADD M 18 A = A + M
AND M 40 A = A AND M
COMP M 28 compares A and M
DIV M 24 A = A / M
J M 3C PC = M
JEQ M 30 if CC set to =, PC = M
JGT M 34 if CC set to >, PC = M
JLT M 38 if CC set to <, PC = M
JSUB M 48 L = PC ; PC = M
LDA M 00 A = M
LDCH M 50 A[RMB] = M[RMB]
LDL M 08 L = M
LDX M 04 X = M
MUL M 20 A = A * M
OR M 44 A = A OR M
RD M D8 A[RMB] = data specified by M[RMB]
RSUB   4C PC = L
STA M 0C M = A
STCH M 54 M[RMB] = A[RMB]
STL M 14 M = L
STSW M E8 M = SW
STX M 10 M = X
SUB M 1C A = A – M
TD M E0 test device specified by M
TIX M 2C X = X + 1 ; compare X with M
WD M DC device specified by M[RMB] = A[RMB]

 

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