LN03R ScriptPrinter Programmer's Supplement

This document, the "LN03R ScriptPrinter Programmer's Supplement," serves as a guide for programmers and system managers on how to effectively use and manage the LN03R printer, particularly when writing or generating PostScript programs. It assumes the reader is familiar with standard PostScript language documentation.

Key content areas include:

• LN03R System Overview: Describes the printer's hardware components (device controller with PostScript interpreter, print engine, paper handling) and software (compatibility with VMS, MicroVMS, Ultrix, MS-DOS, and the need for translators for non-PostScript output). It also outlines host system requirements and ancillary interfaces like the serial port and operator panel.
• PostScript System Parameters: Explains unique LN03R system parameters (e.g., password, job names, margins, timeouts) and their management. It distinguishes between persistent parameters (stored in nonvolatile memory, surviving power cycles) and volatile parameters (active only for the current job). A significant caution is given against general applications exiting the "server loop" to change persistent parameters, as it can damage the printer configuration. The document also details "idle-time scan conversion" for efficient font caching.
• PostScript Extensions: Provides a reference for LN03R-specific PostScript operators and data types. It advises against using these device-specific extensions in general application programs to maintain portability across different PostScript printers.
• Font Metrics: Discusses Adobe Font Metrics (AFM) files, which are ASCII-encoded files containing critical information about character widths, kerning, and composite characters for the 29 fonts supplied with the LN03R.
• Optimizing Performance: Offers strategies to enhance printing speed and efficiency, focusing on PostScript processing. Tips include using smaller operator names, automatic spacing, the bind operator, minimizing procedure calls, scaling coordinate systems, and optimizing showpage and font caching.
• Programming Guidelines for the LN03R: Provides essential advice for writing robust PostScript programs. It covers device control, strict restrictions on certain standard PostScript operators (e.g., exitserver, clear, initgraphics) to prevent conflicts with underlying system layers, and the importance of using save and restore to preserve the program's context state. It also details changes to standard operator behavior (e.g., virtual memory limits, dictionary stack limits), virtual memory management techniques, and proper handling of control and printable characters.
• Appendices: Include comprehensive lists of available fonts and their samples, details on character encoding vectors (Adobe Standard, Symbol, ISO Latin1, DEC MCS), a comparison of compatibilities and differences with the PRINTSERVER 40 (e.g., virtual memory size, communication protocols), and installation instructions for MS-DOS and ULTRIX environments.

In essence, the document serves as a specialized technical reference to enable programmers and system managers to effectively program for and configure the LN03R ScriptPrinter, accounting for its unique hardware, software, and PostScript language extensions.