thir controllers IBM RISC processors that are not specialized for printer data. This is not an issue when
printing in AFP mode. PSF sends IPDS data to the printer in large blocks which the RISC processors
handle quite efficiently.However, in line mode there is no PSF and no IPDS. Instead, the operating system
is sending the data in CCW records, one CCW per print record. The RISC processors are not tuned to
receiving, processing, and acknowledging many small individual records in a short time frame. The more
print records per inch of paper length, the higher processing rate is required.
In general, a job which averages more than 66 print records per 11 inches of paper may not print at rated
speed. Many jobs defined with more than 6 lines per inch will average less than 66 records per 11 inches,
since records are not printed on every line of every page, and since the 3800 has a 1/2–inch unprintable
border at top and bottom of each sheet. However, jobs defined with 6 lines per inch can average more
than 66 records per 11 inches if multiple records are printed per line.This can occur if COPYMODS are
used, or if a technique called line-merge is used. Line-merge is a 3800 technique for printing multiple
records on the same print line. Each of these records requires its own CCW. For this reason, applications
should be reviewed carefully, and arrangements can be made with IBM Printing Systems Division to test
jobs which might have performance problems.
RPQ Installation Considerations
Procedures for installing, operating, maintaining the new 3900 or 4000 printer must be carefully planned
and followed, as with any new printer installation. Some considerations for this step are reviewed in the
final section of this document.
vForms flashes must be converted to electronic overlays, and procedures set in place for usage, storage,
organization and back up of the electronic flashes.
vOperators must be trained in the procedures for executing Compatibility Mode functions on the new
printer. Documentation on the new operator functions and options is included with the RPQ.
vThe RPQ is installed from diskettes by the CE. The diskettes contain microcode for operating
compatibility mode and also for new printer console options for managing the printer in Compatibly
Mode.
vCritical applications should be tested prior to production cut-over.Adequate lead time should be allowed
for overlay generation and testing with applications.
PSF/MVS Line Mode Function
PSF/MVS 2.2 includes a function for 3800 Line Mode Conversion. This capability is documented in the
PSF/MVS 2.2 System Programmer’s Guide, S544-3672. This function allows many jobs which executed in
compatibility mode on the 3800-3 or 3800-6 printers to run without application or JCL changes on a 3900.
Infoprint 4000, or other AFP printer.This function differs from the hardware RPQs in these significant
areas:
vPSF/MVS is required for function. (With the hardware RPQ, PSF is not required if only compatibility
mode jobs are being processed. However PSF is required if AFP print jobs are also to be processed.)
vAFP jobs can be intermixed in the job stream with compatibility mode jobs. The printer does not have to
be switched between two different modes of operation. This may make it easier for your customer to
begin the step toward full AFP implementation.
vAFP fonts must be supplied in place of the 3800 character sets and GRAPHMODs.
v3800 jobs which use the COPYMOD function cannot be processed by PSF Line Mode.
How PSF/MVS Line Mode Works
The PSF/MVS Line Mode function allows PSF to dynamically build and use inline page definition and form
definition resources for compatibility mode jobs. The resources are built using information in the job’s FCB
and JCL parameters for LINECT,COPIES, and FLASH.
PSF accesses the job’s FCB in SYS1.IMAGELIB to obtain information for building the page definition.
Page height will include the full printable page area to allow room for character ascenders and descenders
166 Printer Information