Basic Purpose Printer LB20

This document serves as a Programmer's Reference Guide for application developers intending to interface the LB20 Basic Purpose Printer with a Host Computer. It provides detailed information on the printer's mechanical and electronic functions, focusing heavily on its IBM Proprinter emulation capabilities.

The LB20 printer is designed to handle various documents, including forms (single-sheet, multi-ply up to three copies plus original, with specific size and weight guidelines) and passbooks (vertical or horizontal seam, with detailed dimensions and thickness parameters). It offers a defined printable area and outlines rules for document preparation (e.g., no staples, transparent materials).

Key features and programmable aspects covered include:

• Characters and Attributes: Support for letter, graphic symbols, and special characters with 9-dot vertical resolution. Multiple character pitches (10, 12, 17, 20 cpi) and code pages (437 PC USA, 850 Multi-Latin 1) are available. Various print attributes like double width, emphasized, double strike, underscore, overscore, double height, sub/superscript, and italic are supported.
• Graphics and Spacing: Capabilities for line graphics (two-pass printing) and "All Points Addressable" (APA) bitmap graphics, with options for normal, half-speed dual, normal-speed dual, and high densities. Detailed line spacing options (5, 6, 8 lines per inch, and fine increments) are also provided.
• Communication Interfaces: The printer features an RS232C serial port and a Centronics parallel port. The guide specifies serial port settings (baud rate, data bits, stop bits, parity, flow control using XON/XOFF or RTS/CTS) and pin assignments.
• Status and Error Reporting: Explanations of LED indications for operational status and error conditions, including results of the Confidence Test Routine (CTR).

The core of the guide details commands for IBM Proprinter emulation, categorized into:

• Character Commands: For selecting character sets, code pages, and pitch.
• Downloading and Quality Commands: For defining print quality and downloading characters into the printer's memory.
• Form Length and Margin Commands: For setting document dimensions, top of form, perforation skip, and left/right margins.
• Print Position Commands: For controlling horizontal and vertical print positions, including backspace, carriage return, line feeds, and tabulations.
• Printer Control Commands: For general printer operations like canceling print jobs, form feeding, setting initial conditions, and enabling uni/bidirectional printing.
• Bitmap Graphic Commands: For printing images at different densities and speeds.

The document includes comprehensive command summaries by alphabetical function and ascending hexadecimal code, along with details on compatibility with IBM Proprinter models, listing commands that are ignored or have different behavior. Default settings for various printer parameters are also provided.