If you wished to supply data from your terminal for FILE1, you could
issue the command:
filedef file1 terminal
and enter the data for your program without recompiling.
fi tapein tap2 (recfm fb lrecl 50 block iOO 9track den 800) After issuing this co •• and, programs referring to TAPEIN will access a
tape at virtual address 182. (Each tape unit in the CMS environment has
a symbolic name associated with it.) The tape must have been previously
attached to the virtual machine by the Vft/370 operator.
The AUIPROC option can only be used by a program call to FILEDEF and not
from the terminal. The CMS language interface programs use this feature
for special I/O handling of certain (utility) data sets.
The AUIPRoe option, followed by a fullword address of an auxiliary
processing routine, allows that routine to receive control from DMSSEB before any device I/O is performed. At the completion of its processing,
the auxiliary routine returns control to DMSSEB signaling whether or not I/O has been perfor.ed. If it has not been done, DMSSEB performs the
appropriate device I/O. When control is received from DMSSEB, the general-purpose registers
contain the following information: GPR2 = Data Control Block (DCB) address
GPR3 = Base register for DMSSEB GPR8 = CftS OPSECT address
GPR11 = File Control Block (FCB) address GPR14 Return address in DMSSEB GPR15 = Auxiliary processing routine address
all other registers = Work registers
The auxiliary processing routine must provide a save area in Wh1Ch to
save the general registers; this routine must also perfor. the save
operation. DMSSEB does not provide the address of a save area in
general register 13, as is usually the case. When control returns to the general registers must be restored to their original values.
Control is returned to by branching to the address contained in
general register 14.
GPR15 is used by the auxiliary processing routine to inform to DMSSEB of the action that has been or should be taken with the data block as
follows: Action GPR15=O No I/O performed by !UIPROC routine; DMSSEB will perform I/O. GPR15<O GPR15>O I/O performed by !DIPROC routine and error was encountered. DMSSEB will take error action. I/O performed by AUXPROC routine with residual count in GPR15; DMSSEB returns nor.ally.
GPR15=64K I/O perfor.ed by lUIPROC routine with zero residual count. CMS Introduction 2-47

DOS/VS Support Under eMS eMS supports interactive program development for DOS/VS Release 31, 32,
33 and 34. This includes creating, compiling, testing, debugging, and
executing commercial application programs. The DOS/VS progra.s can be
executed in a eMS virtual machine or in a eMS Batch Facility virtual
.achine. DOS/VS files and libraries can be read under data sets can be read and written under The CMS DOS environment (called CMS/DOS) provides many of the sa.e
facilities that are available in DOS/VS. However, CMS/DOS supports only
those facilities that are supported by a single (background) partition.
The DOS/VS facilities supported by CMS/DOS are: • DOS/VS linkage editor support • DOS/VS Supervisor and I/O macros • DOS/VS Supervisor control block support • Transient area support • DOS/VS VSAM macros
This environment is entered each time the CMS SET DOS ON command is
issued; VSAM functions are available in CMS/DOS only if the SET DOS ON (VSAM) command is issued. In the CMS/DOS environment, CMS supports many tOS/VS facilities, but does not support as simulation. When you no
longer need DOS/VS support under CMS, you issue the SET DOS OFF command and DOS/VS facilities are no longer available. CMS/DOS can execute programs that use the sequential (SAM) and virtual storage access method (VSAM), and can
libraries.
access method
access DOS/VS CMS/DOS cannot execute programs that have execution-time
restrictions, such as programs that use sort exits, teleprocessing
access methods, or multitasking. DOS/VS COBOL, DOS PL/I, and Assembler
language programs are executable under CMS/DOS. All of the CP and CMS online debugging and testing facilities (such
as the CP ADSTOP and STORE commands and the CMS DEBUG environment) are
supported in the CMS/DOS environment. Also, CP disk error recording and
recovery is supported in CMS/DOS. With its support of a CMS/DOS environment, CMS becomes an important
tool for DOS/VS application program development. Because CMS/DOS was
designed as a DOS/VS program development tool, it assumes that a DOS/VS system exists, and uses it. The following sections describe what is
supported, and what is not. CMS SUPPORT FOR OS AND DOS VSAM FUNCTIONS CMS supports interactive program development for
using VSAM. CMS supports VSAM for as programs
as/vs COBOL, or OS PL/I programming languages; or
in DOS/VS COBOL or DOS PL/I programming languages. VSAM for OS or DOS assembler language programs. OS and DOS programs written in VS BASIC, DOS programs written CMS does not support
2-48 IBM VM/370 System Logic and program Determination--VoluMe 2