Small-C
Encyclopedia
In computing
, Small-C is both a subset of the C programming language
, suitable for resource-limited microcomputer
s and embedded system
s, and an implementation of that subset. Originally valuable as an early compiler
for microcomputer systems available during the late 1970s and early 1980s, the implementation has also been useful as an example simple enough for teaching purposes.
The original compiler, written in Small-C for the Intel 8080
by Ron Cain, appeared in the May 1980 issue of Dr. Dobb's Journal
. James E. Hendrix improved and extended the original compiler, and wrote The Small-C Handbook. Ron bootstrapped
Small-C on the SRI International
PDP 11/45 Unix
system with an account provided by John Bass for Small C development (with management permission, provided the compiler sources were released as public domain). Small-C was important for tiny computers in a manner somewhat analogous to the importance of GCC
for larger computers. Just like its Unix
counterparts, the compiler generates assembler code
, which then must be translated to machine code
by an available assembler.
Small-C is a retargetable compiler
. Porting Small-C requires only that the back-end code generator be rewritten for the target processor.
, Small-C—now almost twenty-five years old—is still being used, ported, hacked and studied by people who want to learn how a compiler is written.
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, Small-C is both a subset of the C programming language
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
, suitable for resource-limited microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
s and embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s, and an implementation of that subset. Originally valuable as an early compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...
for microcomputer systems available during the late 1970s and early 1980s, the implementation has also been useful as an example simple enough for teaching purposes.
The original compiler, written in Small-C for the Intel 8080
Intel 8080
The Intel 8080 was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design, although without binary compatibility...
by Ron Cain, appeared in the May 1980 issue of Dr. Dobb's Journal
Dr. Dobb's Journal
Dr. Dobb's Journal was a monthly journal published in the United States by CMP Technology. It covered topics aimed at computer programmers. DDJ was the first regular periodical focused on microcomputer software, rather than hardware. It later became a monthly section within the periodical...
. James E. Hendrix improved and extended the original compiler, and wrote The Small-C Handbook. Ron bootstrapped
Bootstrapping (compilers)
In computer science, bootstrapping is the process of writing a compiler in the target programming language which it is intended to compile...
Small-C on the SRI International
SRI International
SRI International , founded as Stanford Research Institute, is one of the world's largest contract research institutes. Based in Menlo Park, California, the trustees of Stanford University established it in 1946 as a center of innovation to support economic development in the region. It was later...
PDP 11/45 Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
system with an account provided by John Bass for Small C development (with management permission, provided the compiler sources were released as public domain). Small-C was important for tiny computers in a manner somewhat analogous to the importance of GCC
GNU Compiler Collection
The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...
for larger computers. Just like its Unix
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
counterparts, the compiler generates assembler code
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
, which then must be translated to machine code
Machine code
Machine code or machine language is a system of impartible instructions executed directly by a computer's central processing unit. Each instruction performs a very specific task, typically either an operation on a unit of data Machine code or machine language is a system of impartible instructions...
by an available assembler.
Small-C is a retargetable compiler
Retargetable compiler
In software engineering, retargeting is an attribute of software development tools that have been specifically designed to generate code for more than one computing platform.-Compilers:...
. Porting Small-C requires only that the back-end code generator be rewritten for the target processor.
, Small-C—now almost twenty-five years old—is still being used, ported, hacked and studied by people who want to learn how a compiler is written.