Displays a control record at the console. If another control record is encountered, formats it via D!SSCN. Displays the new control record at the console. Closes the file when end-of-file occurs. Issues a CP CLOSE command to close the card reader. DMSPUN: Ensures that a virtual punch is available; processes PUNCH coiiand options. DMSSTT: Verifies the existence of the file and returns its starting address. If requested, sets up a header record and calls DMSCiR to write it to the console. DMSBRD: Reads a block of data into the read buffer; continues reading untiY-the buffer is filled. Initializes areas to punch records. Issues the SIO instruction to punch the contents of the buffer. Issues a call to DMSIOW to wait for completion of the punch I/O operation. Sets the wait bit on for the virtual punch device and loads the I/O old PSi from NUCOI. This causes CMS to enter a wait state until the
punch operation completes. QMSI!!: Ensures that this interrupt is for the punch. If not, the I/O old PSi is loaded returning CMS to a wait state. If the interrupt is for
the punch, DMSITI resets the wait bit in the I/O old PSW and then loads
the PSi, returning control to DMSIOW. DMSIOW: Places the symbolic name of the interrupting device in the PLIST and passes control to DMSCIO. Checks for SENSE information and handles I/O errors, if any. Handles error returns and resets constants for the next punch
operation. Closes the file and returns control to the co.mand handler, DMSINT. 2 Determines the device type of the printer. Checks out the specified fileid. Checks out the options specified on the PRINT command line. DMSSCN: Verifies the existence of the file and returns its starting address. 2-96 IBM VM/310 System Logic and Program Determination--Volume 2
DMSPRT: Determines the record size to be printed and sets up an appropriate buffer area via a call to DMSFRE. Obtains storage space to be used as a buffer. DMSPRT: Determines whether the file to be printed is a library member or an-input file. Reads a record; continues reading until the buffer is filled. When the buffer is filled* calls DMSPIO to issue the SIO instruction to
begin the print operation. Issues the print SIO instruction and then calls DMSIOW to wait
until the the 1/0 operation completes. DMSIOi: Sets the wa1t D1t for tne virtual printer device and load the I/O-old PSW from NUCON. This causes CMS to enter a wait state until the Ensures that the is for the printer. If not, the I/O old PSi is reloaded, returning CMS to a wait state. If the interrupt is
for the printer, DMSITI resets the WAIT bit in the I/O old PSi and loads
that PSi, returning control to DMSIOW. Places the symbolic name of the device in the last word of the PLIST and passes control to DMSPIO. Performs channel testing and handles errors. TIO instructions
and sense SIO instructions are issued during the test processing@ These
operations are synchronized using DMSIOi and DHSITI in the manner
described above. When the I/O completes successfully, control returns
to DMSPRT. DMSPRT: Determines whether all file records have been printed. If so, control returns to the caller. Otherwise, the address of the buffer is
updated and more print operations are performed. CMS supports the use of ASCII control characters and machine carriage
control characters for the printed output. Part of the CMS implementation depends upon the fact that the set of ASCII control
characters has almost nothing in common with the set of machine control
characters. There are two exceptions to this, the characters X'Cl' and
I'C3'. These two characters, when interpreted as ASCII control
characters, have the following meanings:
Cl Skip to channel 10 before print.
C3 = Skip to channel 12 before print.
The same characters, when interpreted as .achine control characters,
have the following meanings:
C1 Write, then skip to channel 8 after print.
C3 = Do not write, but skip to channel 8 immediately. In printing lines containing carriage control characters, CMS has the
capability of operating in two modes. In the first mode, which may be
called ASCII control characters or machine control characters of either
type are recognized and properly interpreted, except that the two CMS Method of Operation and program Organization 2-97
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