Craig A Brief History Of Apple Computers Work With The Pascal Language

Apple Lisa Computer: History of Apple and Pascal (DTC 1992) A Brief History of Apple Computer's Work with the Pascal Language Written by David T. Cr8ig 736 Edgewater, Wichita, Kansas 67230 07 October 1992 ft ~· ~~"(.~ TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1 APPLE ] [ COMPUTER PASCAL . . . . . . . . . . . . . . . 2 APPLE/// COMPUTER PASCAL .............. 3 APPLE LISA COMPUTER PASCAL . . . . . . . . . . . . . 4 APPLE LISA COMPUTER CLASCAL ............. 6 APPLE MACINTOSH COMPUTER PASCAL ......... 7 APPLE MACINTOSH COMPUTER OBJECT PASCAL . . . 8 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 INTRODUCTION This document provides a concise history of the work that Apple Computer has done with the Pascal computer language. This history was written so that this rather interesting bit of computer technology would be recorded for those with an interest in technical histories like this. The author has never worked for Apple Computer, but has been involved with software development for Apple's many computers since 1978 and has extensively used all of Apple's Pascal implementations. As such, the facts contained herein are based upon personal memories and Apple technical documents and may be inaccurate. The author hopes that those in the know about Apple's Pascal work will correct and extend upon this paper so that the history of Apple's Pascals will be made complete. A Brief' History of' Apple Computer's /lark with the Pascal Language 07 October 1992 • Page 1 of' 9 Apple Lisa Computer Technical Information I Page 0001 of 0009 Apple Lisa Computer: History of Apple and Pascal (DTC 1992) APPLE ][ COMPUTER PASCAL Apple first became involved with the Pascal language for its Apple ][ computer series around 1978. At this time Apple's software development efforts were based upon the BASIC and 6502 assembly languages. The key players in bringing Pascal to the Apple ][ were Bill Atkinson and Jef Raskin. Atkinson convinced Apple's management that the Pascal language would be much better for Apple's own software development activities than either BASIC or 6502 assembly. Atkinson and Raskin licensed the Pascal language and development system from the University of California at San Diego (UCSD) and began an internal Pascal development group. Apple's ][ Pascal system included a Pascal compiler, modal editor, 6502 assembler, a powerful filer, and several utility programs (e.g. program segment mapper). The system was controlled via a command line user interface. The Apple ][ Pascal compiled to P-Code which was based upon byte codes and a stack architecture. This P-Code was interpreted by an interpreter written in 6502 assembly. 6502 assembly language routines could also be linked with P-Code programs. Identifiers in ][ Pascal were recognized only up to 8 characters, a painful limitation which Apple did not remove until its Macintosh MPW Pascal. Pascal's memory use was restricted to 64k bytes due t…