Programming instructions

OPERATE CLASS

The instructions of the Operate class require one cycle for their execution.

The octal code (bits O-3) for this class is 74. The operations specified by

bits 4-17 are called micro-instructions. The functions of each micro-

instruction are described in the following table. The Event Time indicates

when the operation is performed in the course of the cycle. Times 0, 1,

and 2 occur in that order in the latter part of the cycle.

Except for the restrictions indicated at the end of the table, micro-

instructions may be combined in a single instruction. The bit assignment

of the Operate class micro-instructions is shown in Figure 6.

Opr-740000

Invert

Sense

Of Skip

1 If bit 8=1 If bit 7 = 1

5 16 1 7 181 9 1101 11 ~12~13~14~15~16~17

ttt ttttttttt

da cl1

snl sza sma hlt rar ral oas cml cma

Additional

Rotate

Figure 6 - Operate class instruction - bit assignment

MNEMONIC

OCTAL EVENT

SYMBOL CODE TIME

OPERATION

opr

cla

740000

750000 2

cma 740001 3

cll

744000 2

cml 740002 3

Operate. Indicates the Operate class. When

used alone, performs no operation; the

computer proceeds to the next instruction.

Clear AC. The AC is cleared to 0.

0 => C(AC).

Complement AC. Each bit of the AC is com-

plemented.

C(AC) => C(AC).

Clear Link. Link is set to 0.

0 => C(L).

Complement Link. C(L) => C(L).