Apple 310 manual PostScript Language Changes, Printererror

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C H A P T E R 2

LaserWriter Select 310 Software

printererror

Syntax

status tries printererror –

Deﬁnition This procedure is called during execution of showpage or copypage if the printer mechanism reports an error such as out of paper, no paper tray, paper jam, cover open, and so on.

status is an integer that encodes details of the error condition. It is device dependent and is not documented in this developer note.

tries is the number of times printererror has previously been called during the same showpage or copypage. If printererror returns, the printed operation is retried. If it aborts, by executing stop, the printing operation is abandoned.

Standard procedure: printererror interprets status and generates a PrinterError status message. It then returns, allowing printer errors to be retried indeﬁnitely.

Error stackoverflow

PostScript Language Changes

Several additions have been made to the PostScript language, which is used by the LaserWriter Select 310 printer , and by certain other PostScript printers. The additions are upwardly compatible and do not affect the function of any existing PostScript language programs.

Note

PostScript language programs that are intended to be compatible with all PostScript printers should not use the new features. The program can determine whether or not the new features are present, and it can invoke them conditionally. ◆

The new features described in the following sections include:

■packed arrays, which provide a means of cutting down on the amount of virtual memory allocated for the storage of executable arrays

■immediately evaluated name, a new kind of name token, that causes names in procedures to become tightly bound to their values

■a different kind of operation for the font cache

■a new general sampling and halftoning technique that allows a larger class of sampled images to be transferred from a binary source image to the raster output device

■a different method of handling end-of-line recognition

This section also lists the new operators used in the LaserWriter Select 310 printer.

PostScript Language Changes

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Contents Apple LaserWriter Select 310 Printer Limited Warranty on Media and Replacement Contents Page Communication Channels Page Figures and Tables Page What This Note Contains About This NoteOther Reference Material Conventions Used in This NoteApda For More InformationPage LaserWriter Select Hardware1 LaserWriter Select 310 Hardware ROM Serial Port for RS-232C Devices Communication Ports2An 8-pin serial port connector Centronics Parallel ConnectorPstrobe Signal Status Lights ROM Capability Memory CapabilitiesBatch Mode Basic OperationDram Expansion Types Interactive ModePaper Handling 7Paper handling options Page LaserWriter Select 310 Software Software Overview Adobe PostScript Programming LanguagePostScript Interpreter Types LaserWriter Select 310 DriverSelects the paper tray containing A4-size paper and sets Compatibility Operators Software ParametersProduct Strings Communication Device ParametersStatusdict Setting Compatibility Operators Device Idlefonts Setting System ParametersCheckpassword DefaulttimeoutsRamsize PrinternameProduct ProductASetdefaulttimeouts SetpasswordSetidlefonts Setprintername Setting Page Device ParametersDefaultmultipurposetraysize DefaultpapertrayPagestackorder ManualfeedtimeoutManualfeed MarginsSetdefaultmultipurposepapertraysize PapersizePapertray Setdefaultpapertray SetdostartpageSetmargins Setpagestackorder SetpagetypeSetpapertray Jobname Setting User ParametersJobtimeout SetjobtimeoutSetting Device Parameters WaittimeoutSetsoftwareiomode Setting Communication Parameters SoftwareiomodePacketbackchannel Setpacketbackchannel SccbatchSetting Engine Device Parameters SetsccbatchDarkness Currentpacking Setting Extensions to PostScript LevelSetdarkness CurrentcacheparamsSetcacheparams PackedarraySetpacking Printer Error ParameterPostScript Language Changes PrintererrorPacked Arrays Packed Arrays Versus Ordinary ArraysCreating Packed Arrays Immediately Evaluated Names Changes in Font Cache Operation Device Resolution ImagesEnd-of-Line Recognition New Operators TrueType FontsCommunication Channels Baud Rates Serial CommunicationParity Settings Flow ControlDTR Flow Control XON/XOFF Flow Control SCC Operator EncodingSimple Communication Protocol Communication ProtocolsBinary Communication Protocol SOH CTL-A Parallel Interface Communicating with an IBM PCDTR Flow Control for PC Communication Serial InterfaceXON/XOFF Flow Control for PC Communication Communication DynamicsStatus Queries and Spontaneous Messages Errorerror OffendingCommand operator %%