Computer Science Laboratory
May 11, 1978
FromDan Swinehart
SubjectLet’s Talk About Printing!
Filed As[Maxc]<Gr-Docs>PrintingUpdate.Press
This document announces two major changes (and a minor one) in the PARC printing environment, to take place on June 15, 1978. For more information, please refer to
Printing at Palo Alto, [Maxc]<Gr-Docs>Printing.Press (23 pp.)
This document describes the planned changes in more detail. It also provides a detailed description of the current printing environment, including a massive bibliography of local printing literatiure, and a comprehensive glossary.
The Demise of Ears
The Palo/Ears system, because of its advancing age, is becoming quite difficult to maintain. For this reason, a second floor tribunal has decided that Palo will be removed from service on June 15. Long and faithfully has it served.
Dover/Spruce printers are now functionally competitive with the Ears system, although the number of available, useful fonts is somewhat diminished, particularly landscape fonts (see page 3.) Spruce cannot achieve the heavy-load throughput of Ears at present. The multiplicity of printers should ease this situation, as should future performance improvements.
Most EARS format files currently in existence, and those that will continue to be produced by Pub, contain directory entries (Doculists) that allow the PressEdit program to produce equivalent Press files from them. We hope it will be possible to salvage the few old EARS format files that PressEdit cannot currently handle. We strongly recommend conversion to methods that do not require this intermediate step.
Character Widths
On the same date we will distribute a new Fonts.Widths file, correcting the width specifications for our major document fonts (Helvetica and TimesRoman). Previously produced Press files should continue to print reasonably accurately, although they may not do so forever. Subsystems that create Press files will be required to supply the current date (machine readable format) in a new field within each new Press file (see page 2). Methods will be available for converting both old and new EARS files, using the widths appropriate for each.
Dover/Sequoia Printing Resolution
We are currently operating all the Dover printers in Palo Alto at 350 dots/inch. For a variety of technical reasons, we will switch to 384 dots/inch as part of the June 15 cataclysm. With one important exception, users will not notice the change. The exception is that, again for technical reasons, Orbit printers at 384 dots/inch are limited to a 10.6" high page. Dovers and Sequoias will thus enforce a .4" top margin, which may cause some information to be "clipped" from the page. Pimlico output will be unaffected.
Guide to Implementors of Press Files
After the June 15 date, a Press format file created using the new width information will print incorrectly unless it also contains a valid machine-readable date in its document directory. This is the 32-bit "seconds since January 1, 1901" time value used on the Alto. The time field occupies the previously unassigned words 6 and 7 in the Press document directory (DDV structure in BCPL.) The BCPL definitions file
contains an updated DDV structure definition. Systems that follow this policy may be released any time prior to June 15; the appearance of the new date field will do no harm to current printing systems.
Notice that words 10 and 11, previously unused, are now also defined. These words may contain the page numbers of the first and last pages of the Press file that are to be printed. If both are -1 or 0, the whole file is assumed. No current printing software honors these fields, but it is planned that they will.
The press file documentation, [Maxc]<Gr-Docs>PressFormat.Press, also reflects these new fields, or will soon.
I will be checking with all the people that I know are responsible for generating Press files to be sure there are no difficulties. If you think you may not be on this list, please inform me of any problems you have.
Spruce Fonts for PARC Printers
(effective June 15, 1978)
FamilySize (pt.)Face
TimesRoman8, 10, 12MRR, BRR, MIR, BIR
Helvetica7, 8, 10, 12MRR, BRR, MIR, BIR
Gacha8, 10MRR, MIR
Cream10, 12MRR, BRR, MIR, BIR
Apl8, 10MRR
Dots256micaMRR (for Alto bit maps)
Landscape Fonts:
TimesRoman8MRR, MIR, BRR
TimesRoman10MRR, BRR
Helvetica6MRR, MIR