ICL 1900 Series George 3 Operating System Commands

MAKEVCC (MV)

Function

Introduces to the system a virtual 7900 communications processor unit with details of its configuration.

Format

MAKEVCC unit number,file description

where
unit number must be expressed in the form of Unumber. It defines a unique operator number, in the range 256 to 511, to be used for referring to the virtual 7900 and its identifiers.
file description must be a unique absolute file name. It refers to a basic file which describes the configuration of the virtual 7900. The file must be trapped to :SYSTEM for reading. See note 1 for the format of this file.

Forbidden contexts

NOT OPERATOR, REMOTE

Execution

The following checks are made before the virtual 7900 is created:

1. The command has the correct format.
2. The unit number is in the required range and is not known to the IDF.
3. The file is a basic file which is online, available, trapped to :SYSTEM for reading, not a multifile; and contains a valid configuration

When the MAKEVCC command has been successfully executed, the following message is output on the operator's console:

    VIRTUAL 7900 unit number NOW EXISTS

Example

MAKEVCC U256,:SYSTEM.V7900CONFIG

Notes

1. Configuration file format specification
   
   Each record in the file defines a seperate identifier and is of the format
   
   Inumber type subtype
   
   where
   
   number is an identifier expressed as a decimal integer in the range 1 to 4095 and corresponds to an identifier number in Communications Manager for RJE use.
   
   type is the corresponding device type of the identifier and must be one of the following strings:
   
   CR  signifies an RJE card reader
   LP  signifies an RJE line printer
   TW  signifies an RJE operator's console
   TR  signifies an RJE paper tape reader
   TP  signifies an RJE paper tape punch
   VDU signifies a MOP VDU
   
   subtypes is optional and is used to specify the identifier's device characteristics. The following strings may be given, in any order:
   
   7502    signifies a soft format loop line printer
   SPOOLING signifies a device with spooling capability
   
   The type and subtype nmemonics corresponds to mnemonics in an IDFLIST.
   
   Spaces are not allowed between I and number, but elsewhere they are not significant and are recommended for clarity.
   
   Identifier numbers must be defined in ascending numerical order. As with real 7900 identifiers it is more efficient if they are consecutive.
   
   The configuration file must be terminated by a record containing **** as the first four characters.
   
   If any of the above conditions are violated, the number of the relevant record (numbering from zero) is output in an error message and the command is aborted.
   
   Example
   
   I20 LP 7520 SPOOLING
   I21 CR
   I22 TW
   ****
   
   
2. Successful completion of the MAKEVCC command results in an entry in :SYSTEM.IDF for the virtual 7900 unit, the unit being marked as MOPped OFF and RIGHTed. Also an activity and pseudo device list is created in core for it.
   
   
3. An IDFLIST prints the details of a virtual 7900 under the heading VIRTUAL COMMS CONTROLLER.
   
   
4. A virtual 7900 cannot be ONLINEd by an object program. Thus it is not made known to the HLS.
   
   
5. A virtual 7900 cannot be created without a configuration.
   
   
6. The NEWSPEC parameter to the MOP ON command is not applicable to a virtual 7900 and will be ignored if present. A virtual 7900 must be deleted and re-introduced in order to akter its configuration.
   
   
7. To minimise core overheads, it is recommended that only one virtual 7900 should be in existence at any one time.
   
   
8. If the IDF is 'reconstructed' any virtual 7900s that existed will be deleted.
   
   
9. If a virtual 7900 has no WMC links when it is MOPped ON, the message UNIT unit number HAS BECOME INOPERABLE is output. When Communications Manager is loaded and accesses the virtual 7900 then the RJE adn MOP activities will commence.
   
   

Error Messages

NOT ALLOWED TO USE UNIT z
CONFIGURATION RECORD z INVALID
z IS OUT OF RANGE
z ALREADY EXISTS
THIS COMMAND IS ONLY ALLOWED IN A DME ENVIRONMENT

CANCEL MAKEVCC

Function

Deletes from the system a virtual 7900 communications processor unit.

Format

CANCEL MAKEVCC unit number

Forbidden contexts

NOT OPERATOR, REMOTE

Execution

The specified virtual 7900 is deleted from the system if it exists, is MOPped OFF and not being ACCESSed, and the following message is output on the operator's console:

    VIRTUAL 7900 unit number NOW NON-EXISTENT

Error Messages

z IS NOT A SUITABLE DEVICE
z IS NOT IN REQUIRED STATE