command or the CMS PRINT or PUNCH commands close the file and transfer
it to the RSCS virtual machine. Data specified by the CP TAG command
transmitted across the RSCS network. When
to be transmitted to a remote station via
operand takes the following format:
linkid [userid] [priority]
controls processing of files
a V"/370 user creates a file RSeS, the TAG command text
linkid is the location identifier of the link on which the file
is to be transmitted.
userid is the remote virtual machine that is to receive the
file.
priority is the requested transmission priority (a decimal number 0-99, default The lower numbers have higher
priorities.
Also, ·the CP SPOOL comlRand directs files to the R ses virtual machine. See the publication For details on how to use the ep TAG and SpeeL commands tc control RSCS network functions, see the When Rses handles files being transmitted across the network, the Rses
control program (line driver tasks) issues CP DIAGNOSE instructions.
The DIAGNOSE instruction is the method of communication between a
virtual machine and CP. In VM/370, the machine-coded format for the DIAGNOSE instruction is: 83
rx
ry
Code
Figure
functions
issued.
o 7 8 11 12 15 16
83 rx ry
l DIAGNOSE operation code
User-specified register number
User-specified register number
31
Code
Hexadecimal value that selects a particular ep function, 3 lists
ef those
the DIAGNOSE function codes used
codes, and the Rses modules from
by RSCS, which they
the
are
The RSCS Control Program
Rses is a contrel program composed of a multitasking supervisor and
multiple tasks, which are controlled by the supervisor.
Rses Introduction 3-7

r DIAGNOSE Code 0008 oooe 0014 0020 0024 005C IIssued by
Function IModule(s) Executes a CP command. DETAXS Gets the current time
and date.
Manipulates input spool
files. Perforas general I/O without interrupt.
Determines virtual de­
vice tYFe information.
Edits error messages. DETREX DMTCEX DfiTriGX DETSML DMTNPT D8TS8L D8'INPT DPJTAXS DHTSHL DMTNPT DMTINI DHTREX DETLAX DMTSML DHTREX Figure 3. V8/310 DIAGNOSE Instructions Issued ty the Rses Program The supervisor provides only those functions that cannot be
consistently by the tasks themselves; that is, the superviser
provides only the support necessary to control and coordinate the
execution of the tasks.
In RSCS, a task is a single program or set of subprograms that can
run concurrently and autono.ously with other such programs and subprcgrams, and which uses control functions provided by the
Supervisor.
There are two of tasks: system service tasks and line driver
tasks. The system service tasks are those that provide the system sUFport functions for the supervisor and for other tasks. The line
driver tasks are these that manage the transmission paths to remote
stations and that interact between the remote stations and the system
service tasks and the Supervisor. Each line driver task manages tbe
transmission of files to and from a single remote station.
Figures 12 and 13 in Section 2 show the communications paths tetween the supervisor, system service tasks, line driver tasks, remote
stations, and V8/310 virtual machines.
The RSCS Supervisor
The Rses supervisor is composed of a set of service routines that
provide functions for the tasks that run under them. These service
routines may be called by any task. In general, they provide four kinds
of services: • Task management • I/O management • Interrupt handling • Virtual storage management
3-8 IBM V8/310: System Logic and Problem Determination--Volume 3