HANDLING FILES THAT RESIDE ON OS OR DOS DISKS
By simulating
sequential and same simulated
on DOS disks.
Thus, a DOS running under OS macros, CMS can read, but not write or update, CS pactitioned data sets that reside on OS disks. Using the OS macros, eMS can read DOS sequential files that reside
The OS macros handle the DOS data as if it were OS data.
sequential file can be used as input to an as program CMS. However, an as s9quential or partitioned data set that resides on an
as disk can be written or updated only by an as program running in a
real OS machine. eMS can execute programs that read and write VSAE files from OS programs written in the VS BASIC, COBOL, or PL/I programming languages.
This CMS support is based on the DOS/VS Access Method Services and Virtual Storage Access Method (VSAM) and, therefore, the as user is
li.ited to those VSAM functions that are available under DOS/VS. 2-36 IBM VM/370 System Logic and Program Determination--Volume 2

r I 1 I I Na!.§ XDApt WAIT POST EXIT/RETURN GETMAIN GET POOL FREEPOOL LINK XCTL LOAD DELETE FREEMAIN TIMEI ABEND SPIEl RESTOREI BLDL/FINDI OPEN CLOSE STOll1 OPENJ TeLOSE DEVTYPEI TRKBAL FEOV WTO/WTORI EXTRACTI IDENTIFyt
ATTACHI
CHApl STIMER' DEQ1 SNAp1 ENQI FREEDBUF STAE DETACHl CHKPTI RDJFCBI SYNAD1 BSPI GET/PUT READ/WRITE NOTE/POINT CHECK TGET/TPUT TCLEARQ STAX SVC Number --00- 01 02 03 04 05 06 07 08 09 10 11
13
14
17
18
19 20 21
22
23
24
25
31
35 40 41
42
44
46
47 48 51
56
57 60 62
63
64
68
69
93
94
96
Function Read-or-write direct access volumes Wait for an I/O completion
Post the I/O completion
Return from a called phase
Conditionally acquire user storage
Release user-acquired storage Simulate as SVC 10 Simulate as SVC 10 Link control to another phase
Delete, then link control to another
load phase
Read a phase into storage
Delete a loaded phase user free storage
Get the time of day
Terminate processing
Allow processing program to
handle program interrupts
Effective NOP Manipulate simulated partitioned
data files
Activate a data file
Deactivate a data file
Manipulate partitioned directories
Activate a data file
Te=pcrarily deactivate a data file
Obtain device-type physical
characteristics NOP Set forced EOV error code
Communicate with the terminal
Effective NOP Add entry to loader table
Effective LINK
Effective NOP Access or cancel timer Set timer Effective NOP Dump specified areas of storage
Effective NOP Release a free storage buffer
Allow processing program to
decipher abend conditions
Effective NOP Effective NOP Obtain information from FILEDEF
comlland
Handle data set error conditions
Back up a record on a tape or disk
Access system-blocked data
Access system-record data Manage data set positioning Verify READ/WRITE completion
Read or write a terminal line
Clear terminal input queue
Create an attention exit block
1------·----------------------------------------------------------------- IlSimulated in the transient routine DMSSVT. Other simulation I routines reside in the nucleus.
Figure 7. Simulated OS Supervisor Calls
, CMS Introduction 2-37