
Adapted from Figure 5-5, Computer System Architecture, Third Edition by M. Morris Mano, 1993, Prentice Hall.
Basic Computer Instruction Set |
||
|---|---|---|
|
Symbol |
Hexadecimal code |
Description / binary (register operations) |
|
|
I = 0, I = 1 |
|
|
AND |
0xxx 8xxx |
AND memory word to AC |
|
ADD |
1xxx 9xxx |
Add memory word to AC |
|
LDA |
2xxx Axxx |
Load memory word to AC |
|
STA |
3xxx Bxxx |
Store content of AC in memory |
|
BUN |
4xxx Cxxx |
Branch unconditionally |
|
BSA |
5xxx Dxxx |
Branch and save return address |
|
ISZ |
6xxx Exxx |
Increment and skip if zero |
|
CLA |
7800 |
Clear AC / |
|
CLE |
7400 |
Clear E / |
|
CMA |
7200 |
Complement AC / |
|
CME |
7100 |
Complement E / |
|
CIR |
7080 |
Circulate right AC and E / 0111000010000000 |
|
CIL |
7040 |
Circulate left AC and E / 0111000001000000 |
|
INC |
7020 |
Increment AC / |
|
SPA |
7010 |
Skip next instruction if AC positive / 0111000000010000 |
|
SNA |
7008 |
Skip next instruction if AC negative / 0111000000001000 |
|
SZA |
7004 |
Skip next instruction if AC zero / |
|
SZE |
7002 |
Skip next instruction if E is 0 / |
|
HLT |
7001 |
Halt computer / |
|
INP |
F800 |
Input character to AC |
|
OUT |
F400 |
Output character from AC |
|
SKI |
F200 |
Skip on input flag |
|
SKO |
F100 |
Skip on output flag |
|
ION |
F080 |
Interrupt on |
|
IOF |
F040 |
Interrupt off |