Robert Nordier

Email: info (at)


I work for a US-based semiconductor company as lead software engineer responsible for C compiler development. The software made available here generally reflects an interest in C and UNIX, and the earlier history of computing.

Classic BCPL

BCPL was apparently first implemented by Martin Richards at MIT around 1967, and was a widely-used systems programming language during the 1970s. However, it is chiefly remembered nowadays, because it directly inspired the programming language B, which in turn gave rise to the immensely successful language C.

To anyone interested in the whys and wherefores of C, a passing acquaintance with BCPL is worthwhile. Viewed forwards through BCPL, rather than backwards through Java and C++, many C constructs, and idiomatic C ways of doing things, just make a lot more sense.

Beyond its historical importance, BCPL had intrinsic merits. In retrospect, what particularly impresses, is the elegant simplicity of its compiler. This is well documented in the book BCPL: the language and its compiler by Martin Richards and Colin Whitby-Strevens (Cambridge: Cambridge University Press, 1979).

In its heyday, a great virtue of BCPL was portability. Through the use of INTCODE (a simple assembly language for an abstract machine), the problem of first bringing up the compiler on a new platform was reduced to that of coding an INTCODE interpreter in some high-level language. Such a task might take only a day or two.

The focus here is on "classic" BCPL, as it was around 1979, and the implementations are very close to that described in the BCPL book.

obcpl - Classic BCPL Compiler

This is an x86 (i386) port of the "classic" old BCPL compiler (around 1980) from the Tripos Research Group at Cambridge University. This is a distribution suitable for compiling and running a range of older BCPL programs on 64-bit and 32-bit Linux and FreeBSD systems

As a real, working computer language implementation, that can be studied, modified, and played with, this old BCPL compiler has a good deal to recommend it. The compiler frontend consists of only about 2,000 lines of BCPL code, and (as supplied here) compiles to a static (fully-linked) x86 binary that is less than 36,000 bytes in size.

The present distribution supplies a compiler backend (OCODE to x86 code generator), together with peephole optimizer, and reasonably extensive runtime support. A few revisions have been made to the compiler frontend — it looks for header files in a standard location, for instance — and the runtime incorporates support for UNIX command line arguments and error reporting. Some documentation that formed part of the original BCPL distribution tape is also included, as are a few utility programs.

Download the latest distribution: obcpl-0.9.8.tar.xz.

bcplkit - Classic BCPL Porting Kit

An earlier distribution presents the Cambridge BCPL porting kit, with an INTCODE interpreter and an INTCODE to x86 code generator. Again, the primary version is for FreeBSD and Linux systems. This is a less capable compiler, and the obcpl distribution is to be preferred unless you are interested in INTCODE specifically.

Download the latest distribution: bcplkit-0.9.7.tar.xz.

bcpltape - a BCPL distribution from 1984

Also available are the original BCPL distribution files that the other distributions make use of. The direct source of these files was a tar archive "bcpltape.tgz" that was originally made available — around 1991, I would guess — by Ken Yap. The archive consists of a brief README and fifty-five files named "f01" to "f75", twenty files not being present. The README notes that the supplied archive contains all the files from Martin Richards' "transport" tape with the exception of IBM360 object files. The Cambridge files have date stamps early in November 1984.

As the original porting kit archive seemed to have dropped off the web when I went looking for it, I am making it available here. In redistributing it, I have corrected a number of character mapping problems, apparently caused by incompatible EBCDIC dialects, and have assigned meaningful names to the files and grouped them in directories according to internal evidence.

Download the bcpltape distribution: bcpltape.tar.xz

BCPL Elsewhere

The Classic BCPL for Windows distribution from David Cannon makes use of portions of the software supplied here, and is a simple solution to the problem of compiling old BCPL programs on that platform.

Martin Richards, the originator of BCPL, has continued to develop the language, and has a large and complex distribution of "present day" BCPL available, together with some archive materials, at his home page.


V7/x86 was a port of the Seventh Edition of the UNIX operating system to the x86 (IA-32) based PC: UNIX V7 being the last general distribution — around 1979 — to come from the Research group at Bell Labs, the original home of UNIX. The port was begun in 1999 when "Ancient UNIX" source code licenses first became available, and code was revised, with some enhancements, during 2006-7.

V7/x86 supported ATA (IDE) hard drives, ATAPI CDROM drives, a 1.44M floppy drive, and standard serial ports, in addition to the usual PC screen and keyboard. For easier installation and setup, supplied utilities allowed access to CD (ISO 9660) and FAT (MS-DOS) filesystems.

Extras included a custom UNIX-style x86 assembler, an ACK (Amsterdam Compiler Kit) based C compiler, and several key early UCB software components such as the C shell, the editors ex and vi, and the pager more. Source code was made available under a BSD-style license.

The hardware that v7/x86 was intended to run on — floppy drives, serial ports, and all — is no longer readily available, although it remains possible to try out v7/x86, given suitable virtual machine software, and with careful setup. Be aware, however, that this was beta software and not a polished release: most things work reasonably well, but there are exceptions.

Complete v7/x86 distribution: v7x86-0.8a-all.tar.xz.