ICL 1900 Series George 3 Operating System Commands

SWITCH (SW)

Function

To switch devices between operating regimes in a CME/CME* environment.

Format

  1. SWITCH IN,device description1,....device descriptionn
  2. SWITCH OUT,device description1,....device descriptionn
  3. SWITCH OUT

Except for format 3, at least one device description must be given; where device description may be one of the following:-

  1. A peripheral description specifying a central peripheral (not allowed for MT clusters) or a remote identifier.
  2. XXn (CME*/G3 only). This specifies a central peripheral, which may or may not be known to GEORGE.
    n is the unit number of the peripheral
    XX is the two character nmemonic specifying the device type of the peripheral. It must be one of the following:-
    LP - line printer
    CR - card reader
    CP - card punch
    TR - paper tape reader
    TP - paper tape punch
    ED - exchangeable disc drive
    FD - fixed disc drive
    MC - magnetic tape cluster (n must be the unit number of the first unit)

Format 1 - The peripherals are SWITCHed IN for use by DME.

Format 2 - The peripherals are SWITCHed OUT therefore available for use by VME.

Format 3 - This format allows remote operators to SWITCH OUT their own OPER or MOP terminal users in NO USER context to SWITH OUT their own terminal. No parameters are required.

Forbidden contexts

NOT OPERATOR, REMOTE for central devices
USER for remote bulk devices
USER, NOT REMOTE for format 3

Execution

A check is made that the command is issued in a correct environment. Each parameter in the list is treated independently, so an error in one does not affect the SWITCHing of other devices.

Error Messages

UNIT Un NOT FOUND ON THIS INSTALLATION
UNIT Un IS A MAG. TAPE DECK
UNIT Un IS 7900E
INVALID DECIVE TYPE NMEMONIC XX
UNIT Un NOT TYPE XX
UNIT Un NOT 1ST ON CLUSTER
NO UNITS OF TYPE XX AVAILABLE
THIS COMMAND NOT ALLOWED IN THIS ENVIRONMENT