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Interpretive Language for Text Processing

IP.com Disclosure Number: IPCOM000047015D
Original Publication Date: 1983-Sep-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 14K

Publishing Venue

IBM

Related People

Lotspiech, JB: AUTHOR [+3]

Abstract

A storage-efficient, engine-independent language provides coding of text processing functions particularly useful for an electronic typewriter system which includes a printing mechanism, display, keyboard, and optional diskette mechanism. Means are provided for storing, editing and printing documents. A microprocessor, such as an Intel 8085 with program storage and document storage, controls the mechanisms and provides the document manipulation functions. Involved is the invention of an abstract computer actually implemented in microprocessor code, but on which the actual document processing functions are performed. The code that processes this invented instruction set is referred to as an interpreter and, therefore, the particular interpreter here involved is known as the Language Interpreter for Typewriters (LITR).

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Interpretive Language for Text Processing

A storage-efficient, engine-independent language provides coding of text processing functions particularly useful for an electronic typewriter system which includes a printing mechanism, display, keyboard, and optional diskette mechanism. Means are provided for storing, editing and printing documents. A microprocessor, such as an Intel 8085 with program storage and document storage, controls the mechanisms and provides the document manipulation functions. Involved is the invention of an abstract computer actually implemented in microprocessor code, but on which the actual document processing functions are performed. The code that processes this invented instruction set is referred to as an interpreter and, therefore, the particular interpreter here involved is known as the Language Interpreter for Typewriters (LITR). LITR has the following characteristics: 1. One-byte operand fields of the index register/displacement form. These one-byte operands have special encodings that allow specifying the index registers themselves as operands. 2. A multi-tasking operating system is built into the interpreter, with each task having its own subroutine stack. 3. Operand types, called text structures, are character vectors with an inherent insert point and find point. These text structures: A. Are kept on a text structure stack, and operations can imply the top or top two text structures without using any bits to refer to them explicitly. B. Can serve as the basis for intertask communication and synchronization through SEND and RECEIVE operations. C. Are manipulatable with operations including find, insert, delete, and extract. 4. A supervisor stack on which interrupt routines may save their registers. 5. A memory management scheme in which two pools of different size blocks are maintained. 6. Facilities for reentrant subroutines. 7. Facilities for structured programming branching. 8. Facilities for normal arithmetic and logical manipulation of data (e.g., add, subtract, logical OR, etc.). These facilities: A. A. Can deal with data organized as either 8-bit or 16-bit quantities. B. Can use immediate data since data is part of the instructions. The following are advantages over the conventional method of implementing document processing functions directly in the microprocessor code: 1. 1. Use of LITR reduces the amount of program storage required. This is the result of several factors: A. A. The LITR language was designed to perform all memory accesses using only one byte of code to generate the address. This type of addressing leads to significant program storage compression since most addresses in the native code of the microprocessor (e.g., the 808...