GDSX Manual

LINE^HANDLER Example, Running and Managing
Extended General Device Support (GDSX) Manual–134303
6-5
Running More Application Processes
own CPU number and PIN. $GDS scanned the prompt text for characters to be
converted before issuing a WRITEREAD of the converted text to $TC1. (The
datastream conversion is discussed in Section 5, “DEVICE^HANDLER Example,
Design.”) Finally, the IOP wrote the prompt to the screen and waited for input. Section
7 discusses the functioning of the LINE^HANDLER task in this message flow.
At the application terminal, enter a few text strings in response to the prompts, and
observe what happens. The strings should be uppercase text and in reverse order.
The input string read by the IOP was passed to $GDS, and then on to $A1, which
reversed the sequence of characters in the string. $A1 then issued a call to WRITE the
reversed string to $GDS.#LX.T1. After changing lowercase text to uppercase text,
$GDS issued a WRITE to terminal $TC1, and the IOP displayed the reversed string.
After checking the condition code for its WRITE, $GDS REPLYed to $A1, which then
sent another prompt to the terminal by way of GDSX. The processing is as depicted in
Figure 4-4 on page 4-10.
Running More Application Processes
At the TACL terminal, run two more requesters, again from program file APPL. These
processes will direct their output to logical subdevices T2 and T3, both under LINE
$LX, which is mapped by access name to application terminal $TC1:
> RUN APPL /NAME $A2, OUT $GDS.#LX.T2, NOWAIT/
> RUN APPL /NAME $A3, OUT $GDS.#LX.T3, NOWAIT/
Enter:
> STATUS *, TERM
Note the CPU and PIN values for the new requester processes $A2 and $A3.
At the SCF terminal, enter:
-> STATUS PROCESS $GDS
The STATUS command tells you that there are two TSCODE system tasks, and four
USCODE user tasks.
-> STATUS, SUB ALL
All four user tasks are started. The SU objects have one open each and the LINE object
has three opens, one for each SU.
At the application terminal, enter at least three more text strings and observe the rotation
sequence of the prompts. The three requesters direct their output to logical subdevices
T1, T2, and T3, all of which are mapped to physical device $TC1 under logical LINE
$GDS.#LX.
At the SCF terminal, enter:
-> STOP SU Tn