Fakta:
Obrázek 77.6. Registry PDP-4
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 +---+---+---+---+---+---+---+---+---+---+---+---+---+ | | MA +---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ | | MB +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+ | | PC +---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ | | AC +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ +---+ | | L +---+
Tabulka 77.6. Přehled instrukcí PDP-4
| Mnemo | Code | us | popis | 
|---|---|---|---|
| cal Y | 00 | 16 | Call Subroutine | 
| dac Y | 04 | 16 | Deposit AC | 
| jms Y | 10 | 16 | Jump to subroutine | 
| dzm Y | 14 | 16 | |
| lac Y | 20 | 16 | Load AC | 
| xor Y | 24 | 16 | Exclusive OR: AC ∨ Y → AC | 
| add Y | 30 | 16 | |
| tad Y | 34 | 16 | |
| xct Y | 40 | 8+ | Execute | 
| isz Y | 44 | 16 | Index and skip if zero | 
| and Y | 50 | 16 | AND | 
| sad Y | 54 | 16 | Skip if AC and Y differ | 
| jmp Y | 60 | 8 | Jump | 
| 64 | |||
| iot | 70 | ||
| opr | 74 | ||
| law N | 76 | 8 | 
