Chapter 8 627
Command Definitions SP-Z
SPOOLER
prints the file starts the first copy with the page following the page
number saved in the FLABX and the file's header and trailer (if any)
include (RESUMED) if printing starts anywhere but at the first page.
[+/-]page The page parameter may be used only in conjunction with the SUSPEND,
RESUME, or RELEASE option. The page parameter must be an integer
representing a physical page offset, either absolute or relative, within the
file. Offsets are applied in the order they are entered, whether absolute or
relative. If + is specified, the offset is adjusted forward relative to the
current location by the number of pages specified. If − is specified, the
adjustment is backward. If page is specified without + or -, then printing
resumes at that page, absolute from the beginning of the file. No matter
which combination of offsets are specified, the final location is limited by
the bounds of the file.
A page is defined as follows:
• For CIPER protocol devices: a physical sheet.
• For the HP2680 or HP2688: a physical sheet (which may contain one or
more logical pages).
• For serial printers: the OFFSET option (except for OFFSET=1 or
OFFSET=0, the beginning of the file) is not reliable. No error or warning
message is generated if it is used on such devices; however, results are
unpredictable.
This is because page numbers are accurate only for CIPER protocol
devices and HP2680 and HP2688 page printers.
The spooler's serial printer storage manager makes an approximate guess
as to the correct page. However, it is only a guess based on an extremely
limited interpretation of the spool file by the storage manager, because a
serial printer does not return page data to its storage manager.
The storage manager does not attempt to interpret the spool file data,
looking for escape sequences that may advance paper, eject a page, or
change the page length or line density. This would degrade performance to
an unacceptable level. Instead, it checks the carriage control character
supplied as part of the user's FWRITE intrinisc call.
If that character is an ASCII "1" or an octal 300 (indicating skip to VFC
channel 1, which by industry standard, is a page eject), it notes that this
type of page control is in use and assembles its own checkpoint based on
the location of this record in the spool file. If a RESUME with OFFSET is
later required, it counts these checkpoints to try to find the proper
restarting point. The storage manager ignores any other carriage-control
character.
The page eject carriage control is not required in user data, and many
applications do not use it. In this case, the storage manager is forced to
assume a static number of records (60) per page. Historically, this is the
