GETPOOL: Gets control via an OS LINK macro to IECQBFGI. IECQBPGI allocates an area of free storage using sets up a buffer
control block in the free storage, stores the address of the buffer
control block in the DCB, and then returns control to the caller. This routine (TIME) located in DHSSVT receives control
when a TIME macro instruction is issued. A call is made (by SIO or DIAGNOSE) to the RPQ software chronological timer device, X'OFP'. The
real time of day and date are returned to the calling program in a
specified form: decimal (DEC) binary (BIN), or timer units (TU). All
options of TIME except hundredths of a second HIe are supported. This routine (DMSSAB) receives control when either an
ABEND macro or an unsupported OS/360 SVC is issued. If an SVC 13 was
issued with the DUMP option and either a SYSUDUMP or SYSABEND ddname had
been defined via a call to DMSPLD (FILEDEP), a SNAP (SVC 51) specifying
PDATA=ALL is issued to dump user storage to the defined file. A check
is made to see if there are any outstanding STAE requests. If not, or
if an unsupported SVC was issued, DMSCWR is called to type a descriptive
error message at the terminal. Next, DMSCWT is called to wait until all
terminal activity has ceased, and then, control is passed to the ABEND
recovery routine. If a STAE macro was issued, a STAE work area is built
and control is passed to the STAE exit After the exit routine
is complete, a test is made to see if a retry routine was specified. If
so, control is passed to the retry routine. Otherwise, control passes
to DMSABN unless the task that had the ABEND was a subtask. In that
case, the resume PSW in the link block for the subtask is adjusted to
point to an EXIT instruction (SVC 3). The EXIT frees the subtask, and
the attaching task is redispatched. This routine (SPIE) receives centrol when a SPIE macro
instruction is issued. When it gets control, SPIE inserts the new program interruption control area (PICA) address into the program
interruption element (PIE). The program interruption element resides in
the program interruption handler (DMSITP). It then returns the address
of the old PICA to the calling program, sets the progra. .ask in the
calling program's PSW, and returns to the calling program. All options
of SPIE are supported. RESTORE is a NOP located in DHSSVT. svc to entry points in DMSSOP. If an OS disk
is specified, DMSSVT branches and links to DHSROS. See BLDL and PIND under description of BPAM routines in DMSSVT. See STOW under description of BPAe routines in DMSSVT. OPEN simulates the data management function of
opening one or more files. It is a nucleus routine and receives control from DMSITS when an executing program issues an OPEN macro instruction.
The OPEN macro causes an SVC to DMSSOP. DMSSOP simulates the OPEN macro. The DISP and RDBACK options are ignored by CMS; all other
options of OPEN and OPENJ are supported. CLOSE and TCLOSE are simulated in the nucleus
routine It receives control whenever a CLOSE or TCLOSE macro instruction is issued. The CLOSE macro causes an SVC to DMSSOP. DHSSCP simulates the CLOSE macro. eMS ignores the DISP option; all other
options of CLOSE and TeLOS! ara supported. This routine (DEVTYPE), located in DMSSVT, receives
control when a DEVTYPE macro is issued. Upon entry, DEVTYPE moves Device Characteristic Information for the requested data set into a user
specified area, and then returns control te the user. All options of DEVTYPE are sUFPorted, except RPS, which is ignored.
2-126 IBM VM/370 System Logic and Program Determination--Volume 2

TRKBAL is a NOP located in DMSSVT. Returns control to CMS with an error code of 4 in register
15. This routine (iTO), located in D8SSVT, receives
control when either a iTO or a iTOR macro instruction is issued. For a iTO, it constructs a calling sequence to the DMSCiR function progra. to type the message at the terminal. (The address of the message and its
length are provided in the parameter list that results from the
expansion of the iTO macro instruction.) It then calls the DHSCiT function program to wait until all terminal I/O activity has ceased.
Next, it calls the DMSCiR function program to type the message at the
terminal and returns to the calling program. All options of iTO and iTOR are supported except those concerned with multiple console support.
For a iTOR macro instruction, this routine proceeds as described for iTO. However, after it has typed the message at the terminal it calls
the DMSCRD function program to read the user's reply from the terminal. When the user replies with a message, it moves the message to the buffer
specified in the iTOR parameter list, sets the completion bit in the BeB, and returns to the calling program. This routine (EXTRACT), located in D8SSVT receives
control when an EXTRACT macro is issued. Upon entry, EXTRACT clears tbe
user provided answer area and returns control to the user with a return
code of 4 in register 15. IDENTIFY-SVC 41: Located in DMSSVT, this routine creates a new load request-block-with the requested name and address if both are valid. The new entry is chained from the existing load request chain. The new name may be used in a LINK or ATTACH macro. Located in DMSSLN, ATTACH operates like a LINK (SVC 6),
with additional capabilities. The user is allowed to specify an exit
address to te taken upon return from the attached phase; also, an ECB is
posted when the attached phase has completed; and a STAI routine can be
specified in case the attached phase abends. The DCB, LPMOD, DP!OD, HIARCHY, GSPV, GSPL, SHSPV, SHSPL, SZERO, PURGE, ASYNCH, and TASKLIB
options are ignored; all other options of ATTACH are supported. Because CMS is not a multitasking operating system, a phase requested by tbe
ATTACH macro must return to CMS. CHAP is a NOP located in DMSSVT. TTIMER-SVC 46: Checks to ensure that the value in the timer (hex locaticn--SO) was set by an STIMER macro. If it <was, the value is
converted to an unsigned 32 bit binary number specifying 26 microsecond
units and is returned in register o. If the timer was not set by an STIMER macro a zero is returned in register 0, after setting register 0, the CANCEL oFt ion is checked. If it is not specified, control is
returned to the user. If it is specified, the timer value and exit
routine set by the STIMER macro are cancelled and control is returned to
the user. All oFtions of TTIMER are supported. STIMER-SVC 47: Checks to see if the WAIT option is specified. If so, control-is-returned to the user. If not, the specified timer interval
is converted to 13 microsecond units and stored in the timer (hex
location 50). If a timer completion exit routine is specified, it is
scheduled to be given control after completion of the specified time interval. If not, no indication of the completion of the tiae interval
is scheduled. After checking and handling any specified exit routine
address, control is returned to the user. All options of STIMER are
supported. The TASK option is treated as though the REAL option bad
been specified. CMS Method of operation and Program Organization 2-127