Section 5.3

Special 150- instructions in Programmer's Mode

Contents 

5.3

Introduction

5.3.1

Timing Flag

    .2

Branch Interlock

    .3

H.P.D. interrupt

    .4

Weak Reservations

    .10

Stop

    .11

Abolish

    .12

Date and Time

    .13

Message to Flexowriter or Monitoring Peripheral

    .14

Question to Flexowriter

    .15

Read Directory

    .16

Printout

    .17

Directory information

    .20

Set Monitoring Style

    .21

Set Peripheral Incident

    .22

Set Monitoring Peripheral

    .23

Return from Private Monitoring

    .24

Start new branch

    .25

Return, from peripheral incident (or ENTER) with link routine.

    .30

Reserve peripheral

    .31

Relinquish Peripheral, float and select etc.

    .32

Set Geographical Name

    .33

Load Document

    .34

Set document if loaded

    .35

Set or request document

    .36

Change name

    .40

Get document name, Block 0

    .41

Write Block 0 unconditionally

    .42

Current Block address

    .43

Write non-sequential Block

    .44

Write Block 0 conditionally

    .50

Chapter Change

    .51

Load chapter of semi-built-in program or Basic Input

    .52

Change Drum Reservations

    .53

Change Core Reservations

    .54

Semi built-in Program In

 

5.3  Introduction

Only 3-address form is allowed and may be described as:-

"Call in Orion Monitor Program (OMP) to perform action Z on operands X and Y"

For legal values of Z, the permissible values of X and Y vary for each Z and are described for each 150-instruction.

The 150-instructions involve OMP reading from the drum (except for Z = 1 or 2 or 3 or 4)

The X-address and Y-address fields of legal 150-instructions may be replaced in the normal way and may be preceded by 116 and 117 instructions unless the contrary is explicitly stated.  Replacement and pre-modification involve an additional drum reference.

2-address forms of 150-instructions and illegal values of Z will cause illegal instruction action.

Erroneous values of X and Y will cause reservation violation, peripheral violation or impermissible operand action as appropriate.

If a 150-instruction is obeyed in a branched program then all branches are held up (suspended) until OMP has completed the 150-instruction.

Note that if the instruction format is used e.g. for the second word of a 150/16 or 21 or 50 instruction, then the 3-address instruction format should be used; the 2-address unmodified instruction format causes D8 (TX) bit to be set.