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B compiler for the PDP-8
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8bc -- B compiler for the PDP-8

8bc is a B compiler for the PDP-8.  It compiles standard B for the
PDP-8/E or later computers with or without an EAE.  Programs are
compiled to BIN formatted tapes with an entry point at 0200.

To run programs compiled with 8bc, use the PDP-8 emulator supplied
by the SIMH project.  For example, to compile and run hello.b from
the examples, first compile hello.b into hello.bin:

    $ 8bc hello.b

Then run SIMH: load hello.bin and jump to address 0200 to start the

    $ pdp8

    PDP-8 simulator V4.0-0 Current        git commit id: 6554e0a4
    sim> l hello.bin
    sim> g 200
    HALT instruction, PC: 00321 (JMP 200)
    sim> exit

To build 8bc, first edit Makefile according to your system's needs.
Typically, nothing needs to be adjusted.  You need the following

 * an ANSI C compiler
 * lex (e.g. flex) with libl.a
 * yacc (e.g. bison) with liby.a
 * groff

Then type

    make all

to compile 8bc and

    make install

to install the distribution.  You may need to manually update the manual
database afterwards.

If you are a maintainer, read Makefile carefully for instructions.
Please mark SIMH as an optional dependency/recommended package if your
distribution ships it.  If you perform nontrivial modifications to the
codebase, please have the courtesy to change the version string in 8bc
such that it is clearly visible that the code has been modified and by

Please report bugs on github or by mail to  Please do not
send patches without prior communication.  While I'm willing to fix any
bug you find, I prefer to write the patches myself.

(c) 2019 Robert Clausecker <>
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