BBC Micro Model B
Index Acorn BBC Computer Emulation Software
Free software for Acorn, Iyonix, A9home and RISC OS compatible computers

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BeebIt will only run under the RISC OS operating system. It is compatible with the StrongARM processor, the Iyonix and A9home computers.

There are two versions of BeebIt. BeebIt is maintained by myself and BeebItJ is maintained by James Lampard.
Please read the notes about each version to decide which one suits you the best.
BeebIt BeebIt - BBC Model B Computer Emulator
Version 0.76 (06 Mar 2024) by Michael Foot (enhanced by Crispian Daniels)

  . Emulates Acorn BBC Model B, BBC Model B+ and BBC Master 128 computers.
  . Requires OS, BASIC and filing system ROM images.
  . Runs on all versions of RISC OS from 3.00 to 6.0x.
  . Requires 32 bit system modules in System resources. Available from RISC OS Open.
  . Original release of BeebIt with original 6502 CPU engine.

Download BeebIt 0.76 (120 KB) [32 bit]

Download Source Code for BeebIt

View the list of Changes to BeebIt.
BeebIt BeebItJ - BBC Model B Computer Emulator
Version 1.03 (07 Nov 2007) by James Lampard

  . Emulates Acorn BBC Model B, BBC Model B+ and BBC Master 128 computers.
  . Requires OS, BASIC and filing system ROM images.
  . Runs on all versions of RISC OS from 3.50 to 6.0x.
  . Requires 32 bit system modules in System resources. Available from RISC OS Open.
  . Enhanced release of BeebIt with new 6502 CPU engine up to 20% faster.

Download BeebItJ 1.03 (88140 bytes) [32 bit]

View the list of Changes to BeebItJ.

New features in BeebIt version 0.76:

  . Added OS_ScreenMode enumeration to find available modes.
  . Added switch to full 256 colour mode from 64 colour.
  . Added conversion for 16-bit and 32-bit screen modes.
  . Added weighted colour, greyscale and green palette options.
  . Added 3:2 zoom for screen mode 1024 x 768.
  . Added teletext rounding for high resolution screen modes.
  . Various bug fixes for Stunt Car Rracer, Revs etc.
  . Fixed Low mode screen save overflow when the host Mode 7 is 640 x 500.
  . Fixed 6845 vertical total adjust.
  . Improved detection of floppy disc images.

New features in BeebIt version 0.74:

  . Fixed CPU CLI instruction to allow Lemming Syndrome to work.
  . Corrected display of teletext separated graphics.
  . Allowed a key map file to relocate the key code for the Break key (&80).

New features in BeebIt version 0.72:

  . Fixed CPU address wrapping for post indexed y mode. Allows Pacman Attract to work.
  . Added 1920 x 1050 and 1920 x 1080 screen modes.
  . Fixed VIA timings to correct JSW2 and Elite palette change timings.

New features in BeebIt version 0.70:

  . Fixed M128 shadow memory access to allow By Fair Means of Foul 128K to run.
  . Fixed M128 ROM/shadow RAM bank swapping to allow By Fair Means of Foul 128K to run.
  . Fixed music on Prince of Persia.
  . Fixed screen shot saving.

New features in BeebIt version 0.68:

  . Fixed M128 shadow memory access for the detection of SWRAM to allow Prince of Persia to run.
  . Corrected teletext emulation display issues to allow Prince of Persia to display the title screen correctly.

New features in BeebIt version 0.66:

  . Added screen mode 1280 x 1024 for RISC OS 5 machines.

New features in BeebIt version 0.65:

  . Corrected teletext emulation display issues to allow Granny's garden and Frak! to look correct.
  . Fixed cursor disabling detection so the cursr turns off in Whizzys Mansion and Castle Quest.

Repton 3
New features in BeebItJ version 1.03

  . New version of ZeriBeep, which works with Speech! and now has just 1 version for 26bit/32bit platforms.
  . Some error messages strings are now translated through the Messages file.
  . Now checks which modes are available and will use modes bigger than 640x256, if required.
  . Sprite save now works, even if BeebIt uses bigger than 640x256 mode.
  . If on entering emulation boot fails (ie corrupt MOS rom image) then BeebIt will return to the desktop with an error.
  . On RISC OS 6 now uses BeebIt's own mode 7 emulation, rather than that provided by the VideoTTX module.

Instructions on how to get the OS and BASIC ROM images are supplied in the Help file included with BeebIt. Please read it!
You will need a DFS filing system ROM image if you wish to use files from disc. I recommend using the Acorn DFS 1.20 ROM, but if you cannot get a copy of this, the Watford DFS 1.44 ROM image will work just as well.
The Watford DFS 1.44 ROM can be downloaded from The BBC Lives site <here>.
Other utilities to help with the conversion of BBC files, such as BeebArc, can also be found at The BBC Lives site <here>.
A copy of the original BBC Users Guide can be found at the Retro Kit <here> or at the BBC Lives Site <here>.


The BBC ROMs are still under copyright by Pace Micro Technology Limited.
They are available for download here ONLY to people who still own a BBC B Microcomputer.

Download BBC ROMs (39183 bytes)

Previous versions of BeebIt:

Download Version 0.74 (20 May 2023)
Download Version 0.72 (20 Mar 2021)
Download Version 0.70 (02 Nov 20200)
Download Version 0.68 (22 Apr 2020)
Download Version 0.66 (26 Apr 2019)
Download Version 0.65 (20 Sep 2015) (106882 bytes)
Download Version 0.63 (09 Aug 2011) (102664 bytes)
Download Version 0.62 (02 Jul 2011) (106491 bytes)
Download Version 0.61 (26 Apr 2008) (104050 bytes)
Download Version 0.60 (16 Sep 2007) (103626 bytes)
Download Version 0.58 (24 Apr 2005) (107602 bytes)
Download Version 0.56 (18 Jul 2004)
Download Version 0.53 (28 Jun 2003)
Download Version 0.50 (12 Apr 2003)
Download Version 0.48 (09 Feb 2003)
Download Version 0.46 (21 Dec 2002)
Download Version 0.42.1 (03 Aug 2002)
Download Version 0.40 (18 May 2002)

Reviews of BeebIt:

  . Death Zone Emulation
  . Acorn Gaming: Emulation - BBC Micro
  . The Acorn Emulation Page - Acorn BBC Micro
Software by James Lampard
BeebItFS BeebItFS - BBC emulator filing system
Version 0.33 (24 May 2005)

  . BeebItFS is an 8-bit BBC Micro filing system, written so BeebIt can access files on RISC OS filing systems. It also allows the use of some 6502Em style 'BBC Applications'.

Download BeebItFS (44449 bytes)

BBCFiles BBCFiles - BBC file converter
Version 0.44 (14 Jan 2004)

  . Converts between some of the various types of files used by BBC emulators on Acorn & PC formats.
  . Supports 6502Em style applications & scripts, /ssd dfs disc images (including watford double catalogue), vanilla directories, bbc files with /inf files and /uef files.

Download BBCFiles (212439 bytes)

DSDUtil DSDUtil - DSD image splitter
Version 0.02 (22 Oct 2003)

  . Creates and splits double sided BBC disc images.

Download DSDUtil (21912 bytes)

Before this program will run, you need to have on your computer 'Frontender' (at least version 2.00.5). If you don't already have it you can download it from here.

Software by Richard A. Averill
Version 1.03 (16 Apr 1990)

  . Filing system for DFS floppy discs and DFS disc images.
  . Can be used to create disc images for use with BeebIt.
  . (C) Richard A. Averill, 1990

Richard A. Averill is the original author of ArcDFS. He has given permission for it to be distributed from these pages.

Download ArcDFS (58000 bytes)

Manual for ArcDFS - Cover Page (546122 bytes), HTML/Text (413628 bytes)

Various pieces of BBC software I have written
BBC Cheats - Cheats from BBC Computer games.
6522 VIA - 'C' source code from BeebIt showing how the Rockwell 6522 VIA chip works internally.
Hangman - Teletext version of Hangman.
ParaDrop - Try to land on the target without getting blown off course.
Snake Shoot - Shoot the tail off the snake.
Sniper - Shoot the snipers before they get you.
MICHAELS.SSD - Michael Foot's BBC Programs written between 1985 and 1989.
MSCREEN - Repton 3 screens for the BBC Micro and M128 versions only.
BBC ROM Labels - Labels to print out and label the ROMs inside your BBC Computer. Use thin double sided tape to attach.

Acorn BBC information

Acorn BBC links
The BBC lives!
8-Bit Software The BBC and Master Public Domain Library
The BBC Games Archive

Page designed and written by Michael Foot