[BBC] BeebEm 4.17 20/06/2021

Version 4.17 (Chris Needham, Dominic Beesley)

• Writes to the sound chip are now allowed while sound is disabled. This ensures that the sound chip is in the right state if sound is later enabled.
• Fixed sound frequency write. Setting frequency to zero should initalise the counter to 1024.
• The cursor is now disabled based on CRTC register R8 (see AUG p.366). This fixes the cursor display in Wizzy's Mansion and Pedro.
• Debugger improvements:
  • Fixed instruction 4B (ALR imm).
  • Set the initial input focus so that you can now open the Debugger window and type commands without having to click in the edit box.
  • Added 'over' command. This steps over a JSR instruction, i.e., runs to the next instruction in memory after the JSR.
  • Added a command to show existing labels.
  • Added a command to clear the output window.
  • Fixed help output to show all commands and aliases.
  • Fixed the 'file' command to allow the full 64k address space to be saved.
  • The following commands now prompt for a filename if not given: labels load, save, file, script.
• Mouse input improvements:
  • Changed the right mouse button to control joystick button 2, which is useful for games such as Phoenix and Ripcord that use both joystick buttons.
  • Fixed the "Hide Cursor" option, which caused the cursor to flicker when using the mouse-stick options.
  • Added mouse capture option. To enable, select the "Capture Mouse" menu item and click in the window area. To release the mouse, press Ctrl+Alt.
  • Fixed "AMX L+R for Middle" option.
  • Fixed bug where Master 512 mouse input would sometimes be reversed. Master 512 configures interrupt on raising and faiilng CBx edges alternately. Instead of guessing which should be next, check selected edge in the PCR register.
  • Improved mouse responsiveness when captured.
• Fixed Mode 7 run-length optimisation in the video renderer
• Fixed the teletext font file. The 'W' character had one pixel missing.
• Improved Mode 7 screen capture to avoid distorting the image. Use the 640x512 option for best results.
• Reset double-height state at start of mode 7 screen. This fixes an issue where, if double height is enabled on the last character row of a mode 7 screen, the top row of the screen would also be treated as double height. This effect could be seen in the Twin Kingdom Valley instructions pages.
• Fixed Solidisk Sideways RAM emulation. Writes to RAM bank are selected by User VIA output port B even if the bank selected by &FE30 is writable.
• Fixed Preferences.cfg file backwards compatibility.
• Fixed reading the tube coprocessor selection from BeebEm 4.14 Preferences.cfg files.
• Fixed crash when loading multiple ADFS images from the command line.
• Fixed PrinterEnabled preferences option, which was not being saved/loaded correctly.
• Added BeebEm.user.props.example file and updated the instructions for how to compile BeebEm

Version 4.16 (Chris Needham, Dominic Beesley)

Cylon Attack (A&F Software Ltd., 1983)

• Reintroduced Master 512 co-processor support, following change to the MAME  source code license.
• Added Torch Z80 utility discs and renamed ROM files.
• Fixed Integra-B sideways RAM writes.
• Improved Sprow ARM7TDMI co-processor clock speed accuracy.
• Debug watches now update while the emulator is running.
• Fixed disc image auto-boot.
• Fixed Model B MODE 7 emulation with screen memory at &3C00.
• Fixed 6502 opcodes and removed the Ignore Illegal Instructions menu option.
  • Repton tape loader now works (instructions: 04, 0C, 14, 1C, 34, 3C, 44, 54, 64, 74, 89).
  • Zalaga tape loader now works (instructions: 04, 3C, 44, 54, 5C, 64, 74, 7C).
  • 3D Grand Prix tape loader now works (instruction &80).
  • KIL instructions are executed repeatedly, to emulate hanging the machine.
  • RMBn, SMBn, BBRn, BBSn instructions in 65C02 copro are now implemented.
  • Fixed instruction cycle times.
  • All 6502 and 65C02 opcodes are now recognised in the debugger.
• Removed the "Incorrect disc type selected" warning dialog, which was reporting false positives on valid .ssd files.
• Include complete video state in UEF save state files.
• Clipboard Paste handling no longer overwrites memory.
• Fixed Music 5000 panning, the left and right channels were reversed.
• Fixed use of Jim page select register with Music 5000.
• Added -CustomData command line option.

BeebEm Version 4.20 19 September 2025

• Fixed tape audio output.
• Changed Master 128 CMOS defaults so no ROMs are unplugged, and removed ANFS from the default ROM config.
• VIA timer counter state is now stored in saved state files without losing precision.
• Added a basic (incomplete) emulation of System VIA shift register, modes  2 and 6, and added mode 2 support to the User VIA shift register. Note that only the shift register interrupt is emulated, not the shift register itself, the CB1 output clock, or reading and writing bits to/from CB2.
• Added -Log command line option to write a log file. This is intended for debugging purposes only.
• Fixed the BeebEm installer to not delete existing files under Program Files while installing.
• The SW RAM Board On/Off has been renamed to Solidisk SW RAM Board On/Off, to clarify its purpose.

BeebEm Version 4.20 28 August 2025

Contributors: Chris Needham, Mauro Varischetti, Bill Carr, Daniel Beardsmore,
Steve Inglis, Alistair Cree, Ken Lowe, Mark Usher, Martin Mather, Tom Seddon,
Andrew Hague
 

• Added support for FSD format disk images. This currently only workswith the 8271 and not the 1770 disk controller.
• Fixed support for double-sided SSD disk images (where side 1 tracks follow side 0, as opposed to DSD images, where tracks from side 0 and 1 are interleaved). This only works for 80-track double-sided SSDs, not 40-track.
• * Added icons for disk and tape image file types. The installer now allows you to create file associations for these, and saved state files.
• BeebEm saved state files now use the .uefstate file extension, to distinguish them from UEF tape images.
• Saved state files now include the Master 512, Acorn Z80, Torch Z80, ARM, ARM7TDMI co-processor state, if currently selected.
• Econet improvements:
  • Added -EconetCfg and -AUNMap options, to allow the location of these config files to be set on the command line.
  • Fixed Econet.cfg file parsing.
  • Fixed potential buffer overflow bug.
  • Added support for immediate operations, used by the *VIEW and *NOTIFY commands. These currently only work under Master series emulation.
  • Fixed CTS status bit.
  • Fixed broadcast packet destination to be 255.255.
  • An error is now reported when an sending to an Econet address has not been configured in AUNMap or Econet.cfg.
• Added Master ET support.
• ROM config files (e.g., Roms.cfg) can now include comments. Note that files with comments are not backwards compatible with older BeebEm versions.
• Added -Model and -Tube options, to allow the Beeb model and second processor to be set on the command line. These options override the settings in the preferences file.
• Keyboard mapping improvements:
  • Added Clear button to the key selection dialog box, when defining a user keyboard mapping.
  • Added Italian logical keyboard mapping file.
  • Shift Lock is now mapped to the F11 key by default.
• Tape emulation improvements:
  • Improved tape input data carrier detect emulation.
  • Tape state is now preserved when loading and saving savestate files, for both UEF and CSW files. Saving state is disabled while the tape is recording.
  • Fixed loading CSW files from the command line.
  • Fixed recording (appending) to existing tape image files.
• Improved serial port emulation, and fixed data loss when using serial over a TCP connection.
• Rewrote the Windows serial port implementation. Received characters are now buffered to prevent being lost.
• Added Set Keyboard Links command, which allows you to change the default screen mode and other options (Model B/B+ only).
• Fixed installer to not delete Econet and key map config files.
• Removed the BeebDiscLoad and BeebVideoRefreshFreq environment variables.
• Text to speech improvements:
  • Added menu items to select the text to speech voice.
  • The selected voice and speed are now stored in preferences.
  • Right-Ctrl can now be used instead of Insert to control text to speech output.
  • Speech output can now be stopped and the buffer cleared by pressing Alt+Num Pad 4.
• Added support for ROMs larger than 16kbytes, such as Inter-Word, that use a logic carrier board. Several of these ROM images are now included when you install BeebEm.
• Teletext adapter emulation improvements:
  • Improved teletext TCP/IP client resilience, to properly close the socket if server has disappeared, and to keep up with the latest data from the teletext stream to catch up after the emulation has been paused.
  • Added a dialog box to configure the file names or IP address and port to connect to.
  • The emulated teletext adapter now continues to update its state at the correct frame rate so that teletext sockets are serviced correctly when a source is disabled.
• The "Freeze when inactive" option is now automatically switched off when opening the Debugger window, to ensure the emulation keeps running while the Debugger window is active.
• Added Integra-B IBOS1.26 ROM, and modified the default LANG / FILE parameters for compatibility with both IBOS1.26 and the original Computech IBOS1.20 / 1.20P ROMs. IBOS1.26 is now the default IBOS ROM, and Watford DFS has been replaced by Acorn DNFS, in Roms.cfg.
• Replaced the Acorn Z80 Co-processor ROM with Jonathan Harston's patched version 1.21, which includes a number of bug fixes.
• Rewrote the Master 146818 RTC and CMOS emulation.
• Improved the User Port real time clock (SAF3019P) emulation. Thanks to Ian Wolstenholme for confirming the register write behaviour.
• Fixed sound register reinitialisation after changing the sound sample rate.
• Fixed sound muting when the BeebEm window loses focus.
• Fixed BeebEm window so that it's no longer always on top after exiting full screen mode.
• Fixed "DirectX9 renderer failed. Switching to GDI" errors in fullscreen mode.
• Fixed the WindowsSizes menu options to allow for the menu bar occupying multiple rows, e.g., when at 320x256.
• Fixed teletext mode character alignment.
• Fixed teletext mode hold character and flash/steady and double height.
• Fixed printing to the Windows clipboard, which would previously cause the emulator to slow down or stall.
• When printing to file, the file is now appended to, not overwritten.
• Lots of help documentation improvements.

BeebEm Version 4.19 (Chris Needham, Mike Wyatt, Steve Inglis, Alistair Cree)

• Fixed NMOS 6502 instructions 6B (ARR imm) and EB (SBC imm).
• Fixed timings for instructions 83 (SAX (zp,X)), 8F (SAX abs), B3 (LAX (zp),Y), and BB (LAS abs,Y).
• Fixed 65C12 instruction timings for ADC and SBC in decimal mode, ASL, LSR, ROL, ROR, and BRA.
• Added keyboard shortcuts for changing text-to-speech reading rate. Enable text output reader by default when text-to-speech is enabled.
• Fixed crash in the debugger, where sideways RAM does not contain a normal ROM image.
• Fixed Econet source code cross-compatiblity issue.
• Serial and tape emulation improvements:
  • Fixed serial transmit state: Writing a master reset to the ACIA control register should stop transmitting data. This was causing extra bytes to be written to UEF files when saving to tape.
  • The Tape Control dialog Record button now always prompts the user to create a new UEF file, rather than appending to the currently open UEF file. This change also fixes a bug where the button would do nothing if a CSW file was loaded.
  • Opening the Tape Control dialog no longer causes Block? or Data? errors during loading.
  • The BeebEm version number is now stored in UEF tape files.
• Fixed Master real time clock year handling. The year is stored as the last two digits. Removed the "Master 128 RTC Y2K Adjust" option. Note that the Master MOS still displays years as 19xx, but will accept any century when setting the time using `TIME$`.
• Added debugger support for the BBC Master real-time clock and CMOS RAM.
• Added a new Music 5000 disk image (M5000-4.ssd) that uses a different copy protection patch, to fix the staff editor.
• Added ZipFile project, to create BeebEm.zip distribution. The project runs a Perl script, so requires a working Perl installation.
• The Write Protect On Load menu option is now also applied to files loaded from the command line.
• Improved the Disc Export dialog, which now detects and avoids using file names that are not valid on the host filesystem. The dialog box allows you to double-click an entry to rename files.
• The BeebEm window on Windows 11 is now drawn with rounded corners disabled.

Beebem Version 4.18 (Chris Needham, Alistair Cree, Greg Cook)

• Fixed undocumented 6502 opcodes 2B (ANC imm) and CB (ASX imm).
• Fixed memory reads in undocumented 6502 opcodes.
• Hard disk support improvements:
  •   * Added new Select Hard Drive Folder menu option. This fixes an issue     with the "Options -> Preferences -> Save Disc/Tape/State Folders"   menu option which caused BeebEm to remember the last folder used    to open disk or tape images. This would also set the folder where  BeebEm looks for hard disk images, causing it to create empty
  •     *.dat files in the last folder used. This change also adds a new    HardDrivePath preferences option, separate to DiscsPath.  An error is now reported if opening a hard disk image file fails.
• Improved the emulation of the teletext adapter to implement the full   range of possible states (field sync, data entry window, and video   field). The TFS ROM now acquires pages correctly.
• Fixed key selection in the User Port Breakout Box dialog.
• Fixed 1770 disk emulation to enable automatic disk density selection   in Opus DDOS.
• Fixed the Sprow ARM7TDMI co-processor emulation to ensure fetches are   word aligned.
• Removed documentation for the Emulator Traps menu option,  which has not been implemented yet.