Most z/OS® sites prefer to have the TSO user session automatically switch to the ISPF interface after TSO logon. It is possible, however, to use a limited set of basic TSO commands independent of other complementary programs, such as ISPF. Using TSO in this way is called using TSO in its native mode.

When a user logs on to TSO, the z/OS system responds by displaying the READY prompt, and waits for input, such as in Figure 1.

ICH70001I ZUSER   LAST ACCESS AT 17:12:12 ON THURSDAY, OCTOBER 7, 2004
ZUSER LOGON IN PROGRESS AT 17:12:45 ON OCTOBER 7, 2004
You have no messages or data sets to receive.
READY

The READY prompt accepts simple line commands such as HELP, RENAME, ALLOCATE, and CALL. Figure 2 shows an example of an ALLOCATE command that creates a data set (a file) on disk.

READY
 alloc dataset(zuser.test.cntl) volume(test01) unit(3390) tracks space(2,1)
recfm(f) lrecl(80) dsorg(ps)
READY
listds
 ENTER DATA SET NAME -
zuser.test.cntl
 ZUSER.TEST.CNTL
  --RECFM-LRECL-BLKSIZE-DSORG
    F     80    80      PS
 --VOLUMES--
   TEST01
READY

Native TSO is similar to the interface offered by the native DOS prompt. TSO also includes a very basic line mode editor, in contrast to the full screen editor offered by ISPF.

Figure 3 is another example of the line commands a user might enter at the READY prompt. Here, the user is entering commands to sort data.

 READY
ALLOCATE DATASET(AREA.CODES) FILE(SORTIN)    SHR
 READY
ALLOCATE DATASET(*)          FILE(SORTOUT)   SHR
 READY
ALLOCATE DATASET(*)          FILE(SYSOUT)    SHR
 READY
ALLOCATE DATASET(*)          FILE(SYSPRINT)  SHR
 READY
ALLOCATE DATASET(SORT.CNTL)  FILE(SYSIN)     SHR
 READY
CALL `SYS1.SICELINK(SORT)'
 
 ICE143I 0 BLOCKSET     SORT  TECHNIQUE SELECTED
 ICE000I 1 - CONTROL STATEMENTS FOR Z/OS DFSORT V1R5
             SORT FIELDS=(1,3,CH,A)
 201  NJ
 202  DC
 203  CT
 204  Manitoba
 205  AL
 206  WA
 207  ME
 208  ID
 ***

In this example, the user entered several TSO ALLOCATE commands to assign inputs and outputs to the workstation for the sort program. The user then entered a single CALL command to run the sort program, DFSORT™, an optional software product from IBM®.

Each ALLOCATE command requires content (specified with the DATASET operand) associated with the following:

• SORTIN - in this case AREA.CODES
• SORTOUT - in this case *, which means the terminal screen
• SYSOUT
• SYSPRINT
• SYSIN

Following the input and output allocations and the user-entered CALL command, the sort program displays the results on the user's screen. As shown in Figure 3, the SORT FIELDS control statement causes the results to be sorted by area code. For example, NJ (New Jersey) has the lowest number telephone area code, 201.

Native TSO screen control is very basic. For example, when a screen fills up with data, three asterisks (***) are displayed to indicate a full screen. Here, you must press the Enter key to clear the screen of data and allow the screen to display the remainder of the data.