||BBC BASIC for the PDP11
I started writing BBC BASIC for the PDP11 at university on the late 1980s. It
got as far as starting up, producing its startup message and prompting for
input. Around 2005 I wrote a PDP
emulator and assembler and resumed work on
|PDP11 BBC BASIC running on|
PDP11 Unix Version 6 with an ASR33 Teletype
Unix BBC BASIC uses standard PDP11 Unix TRAPs for I/O, BSD BBC BASIC uses
standard PDP11 BSD TRAPs, so should run on any compliant PDP11 Unix.
RT11 BBC BASIC uses standard PDP11 RT11 EMTs, so should run on any compliant
PDP11 RT11/RSTS system. With a suitable HostIO module BBC BASIC will run on
other PDP11 systems.
BBC BASIC v0.44 (15-Sep-2023):
Running BBC BASIC on Unix
Running BBC BASIC on a PDP11 Tube/CoPro
* bbcbasic, ansi and
basic.unx for Bell Unix and BSD2.9 and earlier
* bsdbasic, bsdansi and
basic.unx for BSD2.10 Unix and later
- Copy the files to an appropriate directory or into a Unix disk image with
a tool such as putr or
UxFiler with 'execute by all'
permissions (eg chmod 555). Rename bsdbasic to bbcbasic, bsdansi to ansi,
and basic.unx to basic. On Unix a suitable location is usually /usr/bin.
- Alternatively, download the bbcpdp.zip archive
and extract it to your Unix system.
- Boot into Unix, log on and type bbcbasic or basic at
the user prompt. basic is a Unix script that starts BBC BASIC
with the output piped through ansi for ANSI screen control.
- bbcbasic is also directly runnable on
- Download basic.rom (13K, v0.44 15-Sep-2023).
- Load it into a bank of sideways RAM, or program it into an EPROM.
- With the PDP11 CoProcessor enabled, PDP11 BASIC will be the default
language and will be entered on Break or with *BASIC.
- Alternatively, the basic.rom file can be run from the PDP11>
- bbcpdp.ssd contains some demo programs, as well as a
copy of basic.rom.
- bbcbasic and basic.sav are also directly runnable on
Running BBC BASIC on RT11, RSTS and UKNC
- Download basic.sav and
copy the file to an appropriate RT-11 disk image with a tool such as
- Alternatively, download the bbcpdp.dsk disk image.
- Boot into into RT-11, select the disk with ASSIGN xyz: DK: where xyz:
is the disk with BBC BASIC on it.
- Type RUN BASIC (or RUN xyz:BASIC where
xyz: is the disk the BASIC.SAV file is on.
Authored by J.G.Harston
Last update: 18-Sep-2023