Subject: 03 Printer Languages or Emulations
Subject: 03.01 HP PCL and PJL
Subject: 03.02 PostScript
Subject: 03.03 Epson ESC/P, ESC/P2
Subject: 03.04 IBM Proprinter
Subject: 03.05 Other Emulations

Subject: 03 Printer Languages or Emulations

Subject: 03.01 HP PCL and PJL

The PCL printer language was developed by Hewlett-Packard for their printers (laser and inkjet). PCL versions are numbered beginning with 1, the current version is 5e. Some words about PCL history (from HP's Printer Language Technical Reference Manual):

PCL 1

Print and Space functionality is the base set of functions provided for simple, convenient, single-user workstation output.

PCL 2

EDP (Electronic Data Processing)/Transaction functionality is a superset of PCL 1. Functions were added for general purpose, multi-user system printing.

PCL 3

Office Word Processing functionality is a superset of PCL 2. Functions were added for high- quality, office document production. (Printers: HP DeskJet family)

PCL 4

Page formatting functionality is a superset of PCL 3. Functions were added for new page printing capabilities. (Printers: HP LaserJet II, HP LaserJet IIP (PCL 4.5))

PCL 5

Office Publishing functionality is a superset of PCL 4. New publishing capabilities include font scaling and HP-GL/2 graphics. (Printers: HP LaserJet III, HP LaserJet 4 (PCL 5e))

PCL versions differ in functionality (e.g. font type support: bitmap fonts, scalable fonts (Intellifonts, TrueType fonts), raster graphic compression methods, HP-GL/2 graphic support).

PCL is the most widely spread printer language in the laser printer market today. Most laser printer manufacturers use an implementation of PCL 4 or PCL 5 for their printers.

PJL (Printer Job Language) was developed also by Hewlett-Packard to provide a method for switching parameters at the job level and for status readback between printer and host computer. PJL may be used at the beginning of a print job for setting some job specific parameters like printer language (PCL, PostScript or others), resolution (300 or 600 dpi), number of copies, etc.

Note: not all HP printers support PJL commands. Sending such a command to a printer not supporting it may cause the printout of the command in the case of a PCL printer. For printers in PostScript mode, the command will cause a PostScript error and prevent the job from printing.

PJL is currently supported by the following HP printers: LaserJet IIISi, LaserJet 4 family, PaintJet XL300 and DesignJet. PJL is also supported in the "5" series LaserJet printers.

According to Ronald F. Guilmette, HP will sell you a set of technical manuals covering PCL and PJL in depth: You _must_ buy the complete "manual bundle". The new part number for the complete PCL manual bundle is: 5010-3997. Cost of this manual bundle is $92.50. The number for ordering this manual bundle is 800 227-8164.

Subject: 03.02 PostScript

PostScript is a page description language produced by Adobe Systems Inc. since the early 1980's. Adobe was formed in 1982 by Dr. John E. Warnock and Dr. Charles M. Geschke. It provides a verbose language of instructions to describe a page of information. While it requires more memory to work with than most page description languages, it was the first widely available product that allowed for control over a large number of fonts and graphical objects.

The first version published in 1985 (the old Red Book) is called Level I, the current implementation (the big Red Book) is called Level II (do not mix these levels with the PostScript version a printer supports, e.g. version 47.0 or version 2011.110, nor with the number in the begin line of any PostScript output like "%!PS-Adobe-3.0"). The PostScript level and to an extent the version of the interpreter too, define the possible operations. For more information see the Red and White Book.

There are several PostScript clones around because of the costly licensing fees for Adobe's interpreter, the best-known surely is GhostScript. Others, built directly into laser printers or addable via cartridges, are Phoenix Page, Brotherscript, Page Styler, True Image, Turbo PS, PDL and KPDL. Naturally they all claim to be 100% PostScript compatible, but this compatibility sometimes ends when it comes to font downloading, font manipulation like adding a metric table or adding new characters, or some other operations. The printing of simple text and graphics is usually no problem with these clones.

Adobe Systems Inc. runs a very good world wide web site http://www.adobe.com where information about PostScript-related products may be found. You may also find technical notes for developers (partly updates for books and manuals), PPD's for most Adobe PostScript printers, and some sample programs.

Beside many other books covering PostScript more or less in detail there are the reference manuals from Adobe Systems Inc. (all published by Addison Wesley Publishing Company):

-

PostScript Language Reference Manual (the old red book), covers PostScript Level I
(ISBN 0-201-10174-2)

-

PostScript Language Tutorial and Cookbook (the blue book), contains annotated examples and short programs
(ISBN 0-201-10179-3)

-

PostScript Language Program Design (the green book), a guide for the design of efficient PostScript programs
(ISBN 0-201-14396-8)

-

Adobe Type 1 Font Format (the black book), specifies the format for Type 1 fonts in detail
(ISBN 0-201-57044-0)

-

PostScript Language Reference Manual, second edition (the big red book), covers PostScript Level II, document structuring conventions and more
(ISBN 0-201-18127-4)

Another source for information about PostScript is the news group comp.lang.postscript. Frequently asked questions are covered by the PostScript FAQ compiled by Jon Monsarrat. It is regularly posted in comp.answers and comp.lang.postscript (the FAQ is also available via FTP from standard FAQ locations, or from ftp://wilma.cs.brown.edu/pub/comp.sources.postscript). In this FAQ you may find pointers to many other books about PostScript.

Subject: 03.03 Epson ESC/P, ESC/P2

ESC/P means Epson Standard Code for Printers.
ESC/P2 means Epson Standard Code for Printers, Level 2.

The printer language ESC/P was originally developed by Epson for use with their early dot-matrix printers. Today it is supported also by Epson inkjet and laser printers as well as by many other dot-matrix printers in the market. ESC/P2 is an enhancement of ESC/P, i.e. it has new functions for font scaling, raster graphic printing, etc.

As with many printer languages, ESC/P or ESC/P2 on printers from different manufacturers may differ slightly in their functionality. Normally the differences are additional functions not provided with the original version from Epson, so beware of using them if you want to support all ESC/P or ESC/P2 compatible printers.

Information about ESC/P and ESC/P2 may be found in the printer manuals of the respective manufacturer. Sometimes it is only a short listing of all available functions (hopefully!) sometimes the functions are declared in depth with examples in BASIC. Character set tables and font width tables may be found there too.

Epson sells the "ESC/P2 Reference Manual", which includes both ESC/P and ESC/P2, as well as a complete description of the differences in commands supported by each printer. The newest version is August 1992, but there is also an addendum which includes the new Stylus Color commands, identified as: "Epson Stylus COLOR Programming Note" dated July 8, 1994.

According to Stuart Williams, a listing of ESC/P codes can be found in ftp://ftp.epson.com/impact/ESCODE.TXT.

Subject: 03.04 IBM Proprinter

The printer language IBM ProPrinter is originally used with IBM printers (IBM Graphics Printer 5152, IBM ProPrinter XL 4201/4202, IBM ProPrinter X24/XL24 4207/4208), today it is supported by many dot-matrix printers as is the case with Epson's ESC/P and ESC/P2. IBM ProPrinter has become another standard emulation for third- party printers. The functionality is different according to the version used or selected during printer setup (XL, X24/XL24 or AGM are some of these versions).

As with many printer languages, IBM ProPrinter on printers from different manufacturers may differ slightly in their functionality. Normally the differences are additional functions not provided with the standard emulations so don't use them if you want to support the standard.

Information about the IBM ProPrinter emulation may be found in the printer manuals of the respective manufacturer. As with ESC/P and ESC/P2 this information can be a short listing of the available functions, or the functions declared in depth. Character set tables and font width tables may be found there, too.

Subject: 03.05 Other Emulations

There are a lot of other unique emulations in the printer market. The following list is therefore far from being complete (the intention is not to describe them exactly, but only to mention them). The order of the listed emulations doesn't say anything about their importance in the printer market.

Advanced Function Printing (AFP):

is used on IBM Mainframes for page printers. It is an architected presentation function set of the Mixed Object Document Content Architecture (MO:DCA), which is part of IBM's System Application Architecture.
You don't actually print with MO:DCA, IPDS (Intelligent Printer Data Stream) is used. The information we have may be out of date, but it used to contain PTOCA (Print Text Object Content Architecture), GOCA (Graphic Object Content Architecture), IOCA (Image Object Content Architecture) as well as some other, non-SAA descriptors (simple image, for example). IPDS is IBM's SAA printing language.
It handles a variety of bit-mapped fonts, simple graphics primitives, and bit-mapped images. Because of the simplicity of the imaging model, it can be used to drive high speed laser printers.

Diablo 630 emulation:

was originally used with daisywheel printers and typewriters. It supports only sequences for tabulation, line and character spacing, attribute selection (bold, double-strike, underline), horizontal movement in both directions, proportional spacing and automatic centering and justification among others. This emulation is sometimes used by other vendors as a base for their printer specific emulation.

CaPSL (Canon Printing System Language):

was the former standard emulation for Canon laser printers. Another name for this emulation is LIPS (Laser-beam Image Processing System). LIPS supports Diablo 630 (the factory setting for the command mode), ISO mode (for printing text data and raster graphics) and VDM mode (for vector graphics and character printing). The story behind CaPSL was that because Canon makes printing engines for HP, they weren't allowed to license HP PCL for their own printers. Hence the need for their own printer language. Canon lasers traditionally included CaPSL, IBM ProPrinter, ESC/P and PostScript emulations, but no PCL emulation). This part of the contract between Canon and HP has apparently expired, since nowadays Canon offers printers with PCL 4 and PCL 5 code. On the other hand Canon no longer seems to offer printers with CaPSL emulation.

RENO:

this is the standard emulation for Agfa printers (P400, P3400 etc.). RENO is a sort of page description language. The functionality is enormous: beside printing text with different scalable fonts, you may draw lines, fill windows with a pattern, use programming statements (if-then-else, repeat-until, set, use and print variables, push and pop operations), download and print your own symbols and transfer data to the printer's RAM or to a hard disk or floppy disk if attached.

Prescribe:

this is a page description language created by Kyocera. The advantage of this language is that you may embed it in any other currently selected printer emulation on the Kyocera machines. Kyocera printers support HP PCL, an HP-GL clone called KC-GL, Epson ESC/P (LQ-850 mode), IBM ProPrinter X24E, Diablo 630, a generic line printer emulation and, as an option, KPDL, a PostScript clone. Being able to use the selected option for text output functions and then switch to an embedded Prescribe sequence for something neat the other emulation doesn't do easily is kind of nice.

DEC:

DEC has their own unique emulations for their laser printers (LN03, LN06). I'll see if my former employer still has the further details I remember them having.

ECMA, ECMA 35:

a printer language standard?

ANSI:

Dan McGowan of Mannesmann Tally tells us that "The Mannesmann Tally printers that support ANSI are based upon the ANSI 3.64 specification. This is a rather loose spec that covers general functions of peripherals. Those of our printers produced in the U.S., in general, support all of the ANSI 3.64 commands pertaining to printer functions.
Those of our printers produced in Germany are flying serial head printers. They support MTPL (Mannesmann Tally Printer Language) which is based upon the ANSI 3.64 spec but includes additional commands unique to serial printer functions/features."