ASSGN ASSGN Use the ASSGN command in CMS/DOS to assign or unassign a system or
programmer logical unit for a virtual I/O device. The format of the ASSGN command is: r , ASSGN SYSxxx \Reaaer ) [ I PUnch I PRinter , , (APllJ \ mode
IGN
TJA
(options ••• [) ]] 2Eii2!!§: r , I ,LOWCASEI L J r , 17TRACKI 19TRACKI L J
-----,
1 I , , , i [TRTCR a] , , [DEN den] I , , L SYSxxx READER
specifies the system or programmer logical unit to be assigned
to a particular physical device. SYSOOO through SYS241 are
valid programmer logical units in eMS/DOS; they may be
assigned to any valid device. The system logical units you may assign, and the devices to which they may be assigned,
are: SYSRDR SYSIN SYSPCH SYSLST SYSLOG SYSOUT SYSSLB SYSRLB SYSCLB SYSCAT Reader,disk,tape
Reader,disk,tape
Reader,disk,tape
Punch,disk,tape
Printer,disk,tape
Terminal,printer
Tape
Disk
Disk
Disk
Disk
The assignment of a system logical unit to a particular device tvpe must be consistent with the device type definition for
the file in your program.
is the spooled card reader (card reader I/a must not be
blocked) • PUNCH is the spooled punch. PRINTER is the spooled printer. TERMINAL is your terminal (terminal 1/0 must not be blocked). TAP[n] is a magnetic tape. n is the symbolic number of the tape
drive. It is either 1, 2, 3, or 4, representing virtual
addresses 181, 182, 183, and 184, respectively. If n is
omitted, TAPl is assumed.
mode specifies the one-character mode letter
assigned to the logical unit (SYSxxx). accessed when the ASSGN command is issued.
of the disk being
The disk must be Section 2. CMS Commands 29

ASSGN IGN (ignore) specifies that any attempt to real from the specified
device results in an end-of-file indication; any attempt to
write to the device is ignored. IGN is not valid when
associated with SYSRDR, SYSIPT, SYSIN, or SYSCLB. UA indicates that the logical unit is to be unassigned. When you
release a disk for which an assignment is active, it is
automatically unassigned. LOWCASE 7TRACK q!RACK TRTCH a
DEN den translates all terminal input data to uppercase.
retains all terminal input data as keyed in.
is the tape setting.
refers to the tape recording technique for 1-track tapes. Use the following chart to determine the value of a. r--- -----, I a Parity converter Translator 1
1 I I 0 odd off off , I OC odd on off I I OT odd off on I I E even off off I 1 ET even off on 1 L--- -----J is tape density: den can be 200, 556, 800, 1600, or 6250
bits per inch (bpi). If 200 or 556 are specified, 7TRACK
is assumed. If 800, 1600, or 6250 are specified, 9TRACK is
assumed. (See Usage Note 8.)
1. When you enter the CMS/DOS environment with the command SET DOS ON, SYSLOG is assigned by default to TERMINAL. If you specify the mode
letter of the DOS/VS system residence on the SET DOS command
line, SYSRES is assigned to that disk mode.
2. You cannot assign any of the following DOS/VS system logical units
with the ASSGN command: SYSRES SYSUSF SYSLNK SYSREC SYSVIS 3. If you assign the logical unit SYSIN to a virtual device, SYSRDR and SYSIPT are also assigned to that device. If you make a logical
assignment for SYSOUT, both SYSLST and SYSPCH are assigned.
4. To obtain a list of current assignments, use the command.
5. To cancel all current assignments (that is, to unassign them), you
can enter, in succession, the commands:
set dos off
set dos on [mode]
6. If you want to access DOS/VS private libraries, you must assign the units SYSSLB (source statement library) , SYSRLB (relocatable library), and SYSCLB (core image library), and you
must issue the DLBL command to establish a file definition. 30 IBM VM/370 CMS Command and Macro Reference