Acornsoft LISP (marketed simply as ''LISP'') is a dialect and commercial implementation of the

Lisp Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized Polish notation#Explanation, prefix notation. Originally specified in the late 1950s, ...

programming language A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

, released in the early 1980s for the

8-bit In computer architecture, 8-bit integers or other data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data bu ...

Acorn Atom The Acorn Atom is a home computer made by Acorn Computers Ltd from 1980 to 1982, when it was replaced by the BBC Micro. The BBC Micro began life as an upgrade to the Atom, originally known as the Proton. The Atom was a progression of the MOS T ...

BBC Micro The BBC Microcomputer System, or BBC Micro, is a family of microcomputers developed and manufactured by Acorn Computers in the early 1980s as part of the BBC's Computer Literacy Project. Launched in December 1981, it was showcased across severa ...

and

Acorn Electron The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was introduced as a lower-cost alternative to the BBC Micro educational/home computer, also developed by Acorn Computers, to provide many of the features of that more expensive mach ...

computers.

History

left, Loading screen (BBC Model B) The interpreter was implemented in

6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small ...

machine-code and was 5.5K in size. It was based on Owl LISP written by Mike Gardner of Owl Computers, which he published for the

Apple II Apple II ("apple Roman numerals, two", stylized as Apple ][) is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The Apple II (original), original Apple II model, which gave the series its name, was designed ...

in 1979. Acornsoft licensed it from Owl Computers in 1981 and developed it for the Acorn Atom and BBC Microcomputer. Acornsoft LISP was released on cassette tape, cassette, disk and ROM cartridge. The ROM cartridge version had instantaneous loading as well as a greater amount of available free random-access memory, RAM for user definitions.

Design

In contrast with large-scale LISP implementations, Acornsoft's variant only had a modest number of built-in definitions as it had to fit in the limited memory space of the 8-bit Acorn computers. The supplied LISP workspace image containing commonly used built-in functions and constants was 3K in size, although this could be deleted if not needed by the user to free up more memory. Supported datatypes included nested lists, 16-bit

signed integer In computer science, an integer is a datum of integral data type, a data type that represents some range of mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are ...

s and strings up to 127 characters in length. LOOP, WHILE and UNTIL keywords were available for program control. A route-finding demo program was supplied as standard with the interpreter. The program can be loaded with the command (LOAD 'ROUTE-M) and tested by typing (ROUTE-M 'OXFORD 'CAMBRIDGE) which for example will display the output (85 CAMBRIDGE BEDFORD WATFORD OXFORD) thus showing the total mileage of the shortest possible route and listing intermediate towns visited.

Documentation

Acornsoft also commissioned a book "LISP on the BBC Microcomputer", by Arthur Norman and Gillian Cattell, published in 1983. Arthur Norman was a lecturer in

computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

, and Gillian Cattell did research into LISP at Cambridge. The book was sold separately from the software and contained examples illustrating use of the Acornsoft specific features such as the ''VDU'' function allowing for machine-specific graphics capabilities. The book also contained working examples including a tree-sorting program, an arbitrary arithmetic package, an animal guessing game, a route finding program, a graphics package, a simple

compiler In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primaril ...

and an adventure game. Acornsoft LISP was reportedly the basis for MetaComCo's QL Lisp product, with Arthur Norman and John Fitch being credited as authors. As a reference, the Acornsoft book by Norman and Cattell was recommended for use with the MetaComCo product.

References

External links

Short discussion of Acornsoft LISP on comp.lang.lisp

* ttps://www.rosettacode.org/wiki/Acornsoft_Lisp Acornsoft LISP at Rosetta Code {{Acornsoft Lisp (programming language) Acorn Computers BBC Micro and Acorn Electron software