Changes.txt

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     SSSS    tt   ee  ee  ll   ll      aa
        SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
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                              Release History
===========================================================================

5.1.3 to 6.0: (December 23, 2018)

  * Note: because of major TIA sound changes, the state file format has
          changed, and old state files will not work with this release.

  * New cycle exact audio core based on work by Chris Brenner (crispy);
    greatly improved audio emulation accuracy (i.e. E.T., Ms. Pacman).

  * Full rewrite of the audio subsystem; resample TIA output to target
    sample rate directly in Stella.

  * Added option to force stereo sound for all ROMs, or to use the
    setting on a per-ROM basis.

  * Threading: decouple emulation from frame rendering.

  * Main loop rewritten; emulating speed and timing is now much more
    faithful (i.e. speed in Pick'n'Pile).

  * Added preliminary support for 'CTY' bankswitching scheme and recently
    released 'Chetiry' ROMs.  Special thanks to SpiceWare for adding music
    support to this scheme.

  * UI modernization (new widget look, dialog titles added, dialogs
    refactored).

  * The bankswitch scheme can now be forced by naming the ROM with a
    specific extension (ie: .f8s for F8SC, .fe for FE, etc).  The
    supported extensions are the same as the ones from HarmonyCart and
    UnoCart.

  * Audio settings replaced with new 'audio.xxx' settings.

  * FPS setting replaced with speed setting for adjusting emulation speed.

  * Extra functionality for Time Machine dialog (start/stop recording;
    minor fixes).

  * When logging messages to the System Logger, condense similar messages
    that arrive in batches into fewer messages (including timestamps).

  * Fixes for collision corner cases (during HBlank).

  * Fixed excessive CPU usage while in UI modes (ROM launcher, debugger,
    etc).

  * The 'launcherexts' option has been replaced by a true/false option
    named 'launcherroms', which specifies to show only ROMs or all files
    in the ROM launcher.

  * Changes in 'Game Properties' dialog
    - 'Default' button now affects only current tab like in all other
      dialogs.
    - 'Display' and 'Console' tab changes are now immediate.
    - Fixed bug when selecting 'Auto-detect' format for 50Hz ROMs

  * Fixed bug in autodetecting Genesis controllers.

  * Fixed bug with 'thumb.trapfatal' commandline argument; sometimes Stella
    would lock up when encountering a fatal error instead of entering the
    debugger and displaying a message.

  * Fixed bug in reading from settings file with entries that were empty;
    the parsing was failing.  This affected the 'cpurandom' argument; when
    all options in it were turned off, they were all turned on again during
    the next program run.

  * Fixed bug with 'hold' events; they are now released a short time after
    starting a ROM.

  * When starting Stella for the first time, the first ROM selected will
    determine which path to use by default for subsequent runs.

  * Fixed emulator crash when starting SaveKey ROMs from commandline with
    SaveKey messages enabled.

  * Fixed missing TV format update in frame stats dialog when switching
    display type.

  * Fixed missing debug color update when switching display type.

  * 'Fill to scanline' now works for scanlines above current scanline too.

  * The debugger 'uhex' command is now honoured in CDF and BUS schemes.

  * When switching screenmodes, the sound is now paused and later resumed.
    This fixes popping and cracking sounds apparent on some systems, notably
    OSX when toggling windowed/fullscreen mode.

  * State file format has been optimized to be smaller, and faster loading
    and saving.  This affects both the files saved to your computer as well
    as Time Machine functionality.

  * The ROM name saved in a PNG tEXt chunk now honours the 'snapname'
    setting.

  * Improved snapshots when phosphor is enabled.

  * Updated PAL palette.

  * Added 'Cartridge.StartBank' ROM property, to force a ROM to use a
    specific bank for its reset vector.

  * Added Developer setting, which breaks on reads from write ports.  It
    now detects such conditions in many more cases.  This new way of
    detecting RWP errors obsoletes the old '_rwport' debugger command,
    which has now been removed.

  * Added recently released 'Arkyology' prototype ROM to the database.

  * Added 'Amoeba Jump' and 'Flappy' ROMs (from the Retron77) to the
    database.

  * Fixed 'Street Racer' and 'Video Olympics' ROMs to use paddles in both
    ports.

  * If using SDL 2.0.5 or above, the calculated desktop size now takes
    the taskbar/dock into account (so windows should no longer overlap
    those areas).

  * For UNIX systems: in the ROM launcher, when using symlinks use the
    symlink pathname instead of the underlying filesystem pathname.

  * The UNIX builds now use the system-installed PNG and ZLIB libraries
    by default.

  * The Macintosh builds are now named 'macOS' throughout the codebase to
    reflect the new naming from Apple.

  * For better compatibility, the Windows 32-bit version does not require
    SSE2 anymore.

  * Updated included PNG library to latest stable version.

-Have fun!


5.1.2 to 5.1.3: (June 10, 2018)

  * Fixed crash in OpenBSD when quitting the app, which can also be
    happening on other systems (no reports yet, but the problem is now
    fixed for good).

  * Fixed configure/build scripts to work natively under OpenBSD.


5.1.1 to 5.1.2: (May 20, 2018)

  * Fixed bug with SaveKey autodetection; some ROMs were not correctly
    detecting that a virtual SaveKey device was plugged in.  This notably
    fixes issues in "Super Cobra" and "Scramble" ROMs.

  * Make previously mentioned ROMs use the SaveKey device by default.

  * Fixed bug in UI navigation with joystick hat movement.


5.1 to 5.1.1: (February 21, 2018)

  * Fixed bug in Stargunner ROM starting with a blank screen.


5.0.2 to 5.1: (February 4, 2018)

  * Added "Time Machine" mode, which automatically creates save states
    in user-defined intervals.  The user can navigate back and forth within
    these states inside the emulator and the debugger.

  * Huge improvements to the disassembly view in the debugger and
    disassembly files created:
    - reformatting in debugger for better space utilization
    - much improved code and data detection
    - access tracking and indicators for TIA/IO/RAM adresses in disassembly
    - break vector is tracked (if used)
    - improved cycle count (page penalties, sums created in disassembly)
    - improved handling of instruction masking opcodes (e.g. BIT)

  * Fixed change tracking bug during rewind; changes were accumulated
    instead of being displayed only for the last rewind step.

  * Extended 'rewind' to take a second parameter which allows rewinding
    multiple states.

  * Added 'unwind' command, which undoes the latest rewind(s)

  * Added '<' (unwind) button to debugger.

  * Thumbulator support is not conditional any more.

  * Moved various developer related settings in new Developer Settings
    dialog. These settings now come in two groups (player/developer) and
    allow switching all settings at once.

  * Don't trap write accesses to the datastream pointers in CDF and BUS.
    This fixes -dev.thumb.trapfatal 1.

  * Complete rework of TV mode and ystart autodetection. The new
    implementation is more robust and reduces startup time.

  * Add two "grace lines" of black to the top of the frame when
    autodetecting ystart.

  * Fixed Genesis controller autodetect (Stay Frosty 2, Scramble, etc).

  * Fixed a bug in ystart autodetection that could cause screen jumps.

  * Fixed several bugs in holdselect, holdreset and holdjoyX commandline
    arguments; these now work as expected.

  * Fixed bug in TIA collision handling; it is now disabled in VBlank.

  * Improve TIA PF collision handling during hblank; this fixes a bug in
    Thrust ROM.

  * Fixed wrong display of HM values in debugger after 'HMCLR' has been
    executed.

  * Fixed bug with the debugger 'savedis' command in Windows; it wasn't
    actually saving the files at all.  This has never been reported
    before, so I guess it shows how many people use that functionality.

  * The debugger 'savedis', 'saverom' and 'saveses' now save files in
    a default, user-visible directory (see the documentation for more
    information).  In the case of 'saveses', the filename is now named
    based on the date and time of when the command was entered.

  * Fixed bug with saving snapshots in 1x mode; there was graphical
    corruption in some cases.  Such snapshots also now include any TV
    effects / phosphor blending currently in use.

  * Fixed regular-sized snapshots when phosphor effect was enabled;
    sometimes the image was 'double-blended', resulting in a snapshot that
    was too dark.

  * Fixed crash when selecting 'CompuMate' as a controller type for a non-
    CompuMate ROM; this controller type can no longer be manually
    selected, and will be used automatically used for CompuMate ROMs.

  * Fixed cheat codes, so 7 digits codes are now accepted as described in
    the doc.

  * Fixed swapped ports being displayed wrong in System Logs and debugger.

  * Added options to erase the AtariVox/Savekey flash memory, either for
    all ROMs or only the current one.  Also added a message (configurable)
    when the flash memory is accessed.

  * Access to the AtariVox/SaveKey can be signaled with a message.

  * Added new interface palette 'Light'.

  * Frame stats display made transparent. Also it now displays the real
    frame rate and if the developer settings group is enabled.

  * Improved tab auto-complete in debugger.

  * Added conditional traps and savestate creation to debugger.

  * Added 'Options...' button to debugger which gives access to the options
    menu during debugging.

  * Added debugger pseudo-register '_cyclesLo' and '_cyclesHi', which give
    the number of CPU cycles that have occurred since emulation started.

  * Added debugger pseudo-register '_fcycles', which gives the number of
    CPU cycles that have occurred since the frame started.

  * Added debugger pseudo-register '_icycles', which gives the number of
    CPU cycles of the last instruction.

  * Extended debugger 'dump' command to take a second argument, indicating
    the end of the range to dump data.

  * Improved change tracking; more values are tracked and change tracking
    now works in case of a break too.

  * Added widgets for trackball and SaveKey/AtariVox controllers.

  * Improved emulation of 'FE' bankswitch scheme (no user-visible changes,
    but internally the emulation is much more accurate compared to the
    real thing).  Related to this, improved the debugger support for this
    scheme (you can now switch banks in the debugger view).

  * Added emulation of 7800 initial RAM values and Pause key.

  * Added ROM properties for 'Scramble' ROMs, and updated info for all
    "Champ Games" ROMs.

  * Added ROM properties for 'Zippy the Porcupine' ROMs, and updated
    info for all "Chris Spry (Sprybug)" ROMs.

  * Support UNIX style builds (configure / make) on OSX with both
    XCode / clang and g++.

  * Fixed error when building with uClibc-ng for ARM (thanks to Sergio
    Prado).

  * Updated included PNG library to latest stable version.


5.0.1 to 5.0.2: (August 20, 2017)

  * Improved emulation of Trakball controller, eliminating bias in left/
    right directions.  Thanks to Thomas Jentzsch for the idea and code.
    Related to this, added 'tsense' commandline argument and associated
    UI item, to allow changing sensitivity of mouse trackball emulation.

  * Added preliminary support for multi-threading in the Blargg TV effects
    code.  This is still a WIP; more improvements are coming.  Related to
    this, further optimized the TIA rendering code.  Also added 'threads'
    commandline argument and associated UI item to enable/disable
    multi-threading.  Thanks to Thomas Jentzsch for the bulk of the work
    in this area.

  * Blargg TV effects now no longer cut off the right side of the image
    (by several pixels) in certain cases.

  * Updated CDF scheme to latest version from Spiceware.  In addition,
    this scheme now supports versioning, so older and newer ROMs will
    continue to work.

  * Fixed an annoying bug in Linux, where Alt-Tab'ing out of a window and
    then back again would pass a 'Tab' key event to the app, which in
    most cases would navigate to the next UI element.

  * Fixed potential issue with state file saving and the debugger; under
    certain circumstances a rewind would give a different state than
    before (note that the state file format has changed because of this).

  * Fixed lockups when entering the debugger under certain circumstances.

  * The debugger 'listtraps' command now shows all traps set, not just
    the first one(s).

  * Reverted joystick changes for Decathlon ROMs from last release, as
    it was added by mistake.


5.0 to 5.0.1: (July 23, 2017)

  * Fixed issues in keypad, Genesis and various other controllers that use
    INPTx registers; the emulation is now much more accurate in this area.

  * Various 'Bumper Bash' and 'Decathlon' ROMs are marked as always having
    all 4 directions on a joystick enabled, since they can't be played
    properly otherwise.

  * Added 'Hunchy II' from Chris Walton (cd-w) to ROM properties database.

  * Codebase now uses C++14 features.


4.7.3 to 5.0: (July 16, 2017)

  * Note: because of major TIA/6502/RIOT changes, the state file format
          has changed, and old state files will not work with this release.

  * Stella has moved from Sourceforge to Github.

  * Completely new TIA core is now available, ported from 6502ts by
    Christian Speckner (DirtyHairy). This new core is extremely accurate,
    and matches real hardware in almost every test we've performed.
    New features include:
     - Meltdown emulates correct
     - The lap number in Pole Positions displays correctly
     - Artifacts in the mountains on Snoopy and the Red baron are gone
     - Line artifacts in Title Match Pro Wrestling and Realsports Boxing
       are fixed
     - The spurious line at the left border of Video Chess now displays
       correctly
     - All 32 char text demos from AtariAge now work perfectly (Stella 4
       shows artifacts on several of these)
     - Stella is now the only emulator to display the "Mega Bitmap Demo"
       (atext.bin) from AtariAge correctly
     - Improved starfield effect for missiles (still TODO for ball and
       players)
     - RSYNC emulation has improved, all testcases now match real
       hardware
     - Several other ROMs that have never worked in any emulator are now
       emulated correctly
     - RDY behavior with respect to write cycles is accurate
     - Optional YStart autodetect and more robust frame handling
     - NUSIZ during player draw matches hardware
     - RESMx during missile draw matches hardware
     - Paddle emulation is slightly more accurate. As a consequence, the
       "paddle feel" may be slightly different from Stella 4
     - Fixed debug colors can now be set for each graphical object, from
       a choice of 'red', 'orange', 'yellow', 'green', 'blue' and
       'purple'.  This is accessible through the new 'tia.dbgcolors'
       commandline argument and within the UI.

  * Implemented new phosphor emulation mode, which is much closer to real
    TV output.  Related to this, added ability to change the default
    phosphor blend level in the UI and through the new 'tv.phosblend'
    commandline argument.  Special thanks to Thomas Jentzsch for the idea
    and implementation.

  * TV phosphor effect can now be force-enabled for all ROMs, instead
    of manually setting ROM properties for each ROM.  This is accessible
    in the UI and through the 'tv.phosphor' commandline argument, and
    defaults to being off (or enabled per-ROM).

  * PAL color-loss and Blargg TV effects can now be enabled at the same
    time.  Previously, when Blargg effects were enabled, PAL color-loss
    couldn't be shown.  Related to this, the Blargg effects now use much
    less memory and in some cases run faster than before.

  * Much improved RIOT timer emulation never before seen in any emulator.
    Special thanks to Christian Speckner (DirtyHairy) for the
    implementation, and alex_79 for finding documentation that finally
    describes in more detail how the M6532 chip actually works.

  * Added BUS (experimental) and CDF bankswitching schemes, and also
    ARM Timer 1 support; special thanks to SpiceWare for the code.

  * Fixed bug with SaveKey and AtariVox not properly closing their memory
    files before starting another instance of the same ROM, when the ROM
    was opened in the ROM launcher.

  * Various improvements to the debugger and command prompt:
    - The 'cls' command now only clears the screen, not the history
    - The 'help' command now accepts other commands, and gives extra
      information about the command (ie, 'help breakif' prints extended
      information about the breakif command)
    - Added 'palette' command, which shows a color swatch of the
      currently active TIA palette
    - Added 'debugcolors' command, which shows a legend for 'fixed debug
      colors' mode
    - The previous trap'm' commands now work when setting TIA read
      addresses; previously they only worked for write addresses
    - The previous trap'm' commands are now renamed 'trap', 'trapread'
      and 'trapwrite'
    - The TIA tab now shows 'old' contents of player and ball registers
    - Various UI items are crossed out when disabled, to more clearly
      indicate their current state
    - Various UI items that previously required a double-click to toggle
      (pixel and bit widgets) now require only a single-click.
    - Command completion now works with internal functions and pseudo-ops
      (basically, anything starting with the '_' character)
    - System labels (aka, register names, etc) can now be typed in lower-
      case.  Previously, these labels always had to be uppercase.
    - In general, input error checking is much more strictly enforced
    - Read-only UI items now have a different background color, to
      clearly indicate if an item can be modified.
    - Debugger '.lst' and '.sym' files are now searched based on the name
      of the ROM file, and not on the internal properties name.
    - Snapshots can now be saved by pressing the F12 key (the various
      other ways to save snapshots still exist).

  * Mouse grabbing is now enabled in windowed mode only when the ROM is
    using a virtual analog controller (paddles, trakball, etc).

  * Renamed various trakball-like controllers more accurately: AmigaMouse,
    AtariMouse (previously CX80) and Trakball (previously CX22).  Related
    to this, reduced the resolution of the Trakball by half, to properly
    match real hardware.

  * The stack pointer (SP) is now initialized to $FD instead of $FF, to
    match research done in other 6502 projects.

  * Fixed bug in debugger tracing and displaying the partial TIA image;
    the first time entering the debugger and starting to trace, the image
    was blanked out (black) instead of being drawn in greyscale.  Also, the
    image is now synchronized, instead of being two frames behind.

  * Fixed crash with zipped ROMs that are less than 4K in size; so far
    this bug has only ever occurred in Windows XP, but it's been there
    since Stella 4.1.

  * Fixed bug in 'Rom Audit' functionality; sometimes ROMs without a
    valid properties entry were being renamed as "Untitled.bin".

  * For the entire UI, removed colons and generally made the UI items
    easier to read.

  * When in 'ROM launcher mode', Stella now uses slightly less CPU time.
    More work is required in this area, though.

  * Added ROM properties for D.K. VCS homebrew ROM, thanks to Andreas
    Dietrich.

  * Added slight improvement for auto-detecting Superchip bankswitching;
    the new implementation now works for the NTSC 'Dig Dug' ROM.  Special
    thanks for SpiceWare for the idea and modified implementation.

  * Fixed long-standing bug in 3-voice music in DPC+ bankswitching scheme;
    the music now sounds much more like the real thing.

  * For the Linux/UNIX port:
    - The settings directory now uses the XDG Base Directory Specification.
      In most cases, this means that your files will now be stored in
      '~/.config/stella' instead of '~/.stella'.  To keep your old settings,
      run the following commands from the terminal:
        cd ~
        mv .stella .config/stella

      You will probably need to edit '~/.config/stella/stellarc' and change
      some paths accordingly.

  * For the OSX port:
    - Always use the built-in png and zlib libraries instead of the system
      versions.

    - The preferences file has changed from 'net.sourceforge.Stella.plist'
      to 'Stella-emu.plist'.  To keep your old settings, run the following
      commands from the terminal:
        cd ~/Library/Preferences
        mv net.sourceforge.Stella.plist Stella-emu.plist

  * Updated internal ROM properties database to ROM-Hunter version 13
    (thanks go to RomHunter for his tireless research in this area).
    Related to this, updated the snapshot collection.

  * Updated included PNG and ZLIB libraries to latest stable version.  Also,
    both libraries are now compiled into the app whenever one is selected.
    This fixes issues with a newer ZLIB not working with an older PNG, etc.

  * Updated build scripts for Visual Studio 2017 (Windows) and MacOS
    Sierra (latest version of Xcode), and make these the minimum supported
    versions for building Stella.

  * Updated UNIX configure script to work with the clang 5+ and gcc 7+
    compiler versions, and fixed compile issues on AArch64 and ppc64le
    architectures.


4.7.2 to 4.7.3: (Nov. 21, 2016)

  * Added preliminary support for the 3E+ bankswitching scheme, developed
    by Thomas Jentzsch.

  * Fixed HMOVE positioning bug that occurred under certain circumstances.
    Thanks to Omegamatrix of AtariAge for the bug report and patch to fix
    the issue.

  * Added 'trapm', 'trapreadm', 'trapwritem' commands to debugger prompt.
    These are similar to the non-'m' versions, except that they also trap
    on all mirrors of the given address.

  * Fixed bug in debugger 'reset' command; it wasn't resetting the
    bankswitching, so after a reset the banks were in an undefined state.

  * Updated UNIX configure script to fix a bug where it fails in
    cross-compilation under certain circumstances.  Thanks to Vlad
    Zakharov for providing a patch to fix this issue.


4.7.1 to 4.7.2: (Mar. 25, 2016)

  * Fixed bug when entering and exiting the debugger; sometimes the
    character corresponding to the '`' key would be output in the
    prompt area.

  * Updated DPC+ Thumb ARM emulation code to latest from David Welch.
    In particular, this fixes incorrect handling of the V flag when
    adding and subtracting, but also fixes compile-time warnings that
    I couldn't get rid of before.

  * Updated UNIX configure script to work with GCC 6.x compilers, and to
    remove references to obsolete compiler versions that can no longer
    be used to compile Stella.


4.7 to 4.7.1: (Feb. 13, 2016)

  * Improved TV 'jitter' emulation; the recovery time can now be spread
    over multiple frame, to simulate a real TV taking multiple frames to
    recover.  Related to this, added new commandline argument
    'tv.jitter_recovery' to set the recovery time.  Finally, enabling
    the jitter effect and the recovery time are now accessible through
    the UI.  Special thanks to SpiceWare of AtariAge for the initial idea
    and implementation.

  * Fixed bug with 'Medieval Mayhem' ROMs; the paddle range was set too
    low, and as a result the number of players couldn't be selected.

  * Fixed bug when using more than two input controllers with the same
    name; each controller after the second one was named the same as the
    second one.  This caused the joystick mappings to be lost, since there
    was only information about two controllers being saved.

  * Indirectly fixed issues with Stelladaptor/2600-daptor devices and
    paddles having too large of a deadzone in Linux.  Currently, this
    involves running an external application to set the deadzone,
    since SDL2 does not yet expose this information.  The program is
    called 'evdev-joystick', and will be released separately from Stella.

  * Updated internal ROM properties database to ROM-Hunter version 11
    (thanks go to RomHunter for his tireless research in this area).
    Related to this, updated the snapshot collection.


4.6.7 to 4.7: (January 25, 2016)

  * Improved paddle emulation in several ways:

    - Added ability to specify the maximum range of movement for paddles
      when using a mouse or digital device to emulate the paddle.  This is
      useful since on a real console most paddle games use very little of
      the paddle range, and could result in moving the mouse onscreen with
      nothing appearing to happen (when in effect it was as if you turned
      a real paddle all the way to the end of the range).  This eliminates
      issues in (for example) Kaboom, where there was a huge 'deadzone'
      when moving to the left.  All applicable ROMS in the internal
      database have been updated.

    - The range for paddle emulation now takes an integer from 1 - 20,
      indicating how much to scale movement (ie, how fast the onscreen
      paddle will move when you move the mouse).  The movement itself
      is now also smoother than before.

  * Fixed bug in 'Score mode' in TIA emulation; the TIA object colours
    were correct, but the associated priority was sometimes incorrect.

  * Fixed bug in ROM launcher; selecting 'Options -> Game Properties' after
    loading a ROM would always point to the last opened ROM, not to the one
    currently selected.

  * Fixed bug in storing ROM properties; in some cases, a copy of the
    ROM properties was being stored in the external file when it was
    exactly the same as the internal entry.

  * Added 'CV+' bankswitching scheme, developed by myself and LS_Dracon
    (of AtariAge).  This scheme contains RAM like the CV scheme, and
    also switchable 2K ROM segments by writing to $3D.

  * Added more C++11 updates all over the codebase, and ran Stella
    through Coverity for the first time.  I'm proud to say that Stella
    now has a 0.00 defect rate!


4.6.6 to 4.6.7: (October 28, 2015)

  * Fixed bug when using real paddles plugged into a Stelladaptor
    2600-daptor device; the movement was very erratic.

  * Fixed small logic error in 'MDM' bankswitching scheme.


4.6.5 to 4.6.6: (October 11, 2015)

  * Added 'Alt/Cmd + j' shortcut key and 'tv.jitter' commandline argument
    to toggle the TV scanline jittering emulation added in the last
    release.  Also, this jittering now defaults to off.

  * Fixed bug in 'MDM' bankswitch scheme; bankswitching wasn't being
    done under certain circumstances.


4.6.1 to 4.6.5: (September 26, 2015)

  * Added mappable events for toggling TV color/BW, left difficulty A/B
    and right difficulty A/B.  This means that one key, joystick button,
    etc. can be used to toggle each event.  Thanks to Buzbard of AtariAge
    for the suggestion.

  * Added ability to edit values in more widgets in the debugger.  For
    now, this applies mainly to the various decimal and binary fields.
    More widgets will be made editable in future releases.

  * The TIA now emulates the jitter that occurs when scanline counts
    are not consistent frame-over-frame.  Also, the DPC+ scheme now
    emulates jitter that can occur when using its Fractional Datafetchers
    if the DFxFRACINC registers are not re-initialized every frame.
    Special thanks to SpiceWare for this implementation.

  * Tweaked 'MDM' scheme autodetection to detect that the identification
    string can be in either bank 0 or bank 1.

  * Changed 'hidecursor' commandline argument (and associated UI item) to
    'cursor'.  The new argument allows to set mouse cursor visibility
    separately for both UI and emulation modes.

  * Fixed snapshot bug most noticeable in MacOSX, where taking a snapshot
    of a TIA image sometimes left parts of the UI onscreen (and in the
    resulting picture).

  * Fixed memory leak; the game console wasn't being closed after exiting
    a ROM.

  * For the Windows port: added an application icon for Stella in the
    Control Panel "Add/Remove Programs" list.

  * For the OSX port: Updated build scripts to be compatible with Xcode 7.

  * Updated included PNG library to latest stable version.


4.6 to 4.6.1: (April 22, 2015)

  * Fixed bug whereby text input could not be entered in certain widgets
    in the debugger.

  * Updated UNIX configure script to work with GCC 5.x compilers.


4.5 to 4.6: (March 21, 2015)

  * Finally fixed fullscreen rendering issues on some OpenGL
    implementations in Linux (mostly Intel-specific).  Basically, the
    concept of 'dirty updates' has been removed; the window is now
    updated continuously.  This may also fix issues some people were
    having with triple-buffering in Windows Direct3D, etc.

  * Fixed sound corruption that happened when running a ROM for the
    first time.  This was most obvious under OSX, but occasionally
    happened on other systems too.

  * Reverted some minor C++11 features (std::regex and cbegin/cend
    iterators) in a few places, since otherwise GCC 4.9 is required to
    compile Stella, and it isn't available on many systems yet.  These
    changes allow Stella to be built with GCC 4.8, which is present in
    the latest 'long term release' of Ubuntu.

  * Fixed error messages on state loading; sometimes multiple messages
    were being added together and displayed.

  * Fixed bug when running ROMs using AtariVox controllers; the app would
    crash upon exiting the ROM.

  * Snapshot functionality now works while the emulation is paused.

  * Certain textfields in the UI now have filtering enabled, preventing
    insertion of illegal characters.  This will be extended throughout
    the code in future releases.

  * DataGridWidgets in the debugger now respond to keypad '+' and '-'.

  * Updated included PNG library to latest stable version.


4.2 to 4.5: (January 1, 2015)

  * The conversion to C++11 has begun :)  From this point on, to build
    Stella you will need a C++11 compatible compiler (Visual Studio 2013,
    Clang 3.3, gcc 4.9, Xcode 6, etc).  Eventually, this will bring more
    bug-free and (hopefully) faster code.

  * Fixed major bug with joysticks, where mapping was being lost on reset,
    the app would crash when plugging/unplugging certain sticks, etc.

  * Fixed major (but rare) crash that could occur when state files were
    zero'ed or corrupted.

  * Added dialog which shows the internal joystick database (all the
    joysticks that Stella knows about) and the ability to remove
    (currently unplugged) joysticks from this database.

  * Added preliminary support for 'WD' (Wickstead Design) bankswitching
    scheme, used for a previously unreleased prototype ROM.

  * Improved ZIP file handling, so that it now works as a normal
    filesystem does (it properly shows nested files and directories).

  * The debugger 'reset' command now does a complete system reset,
    instead of simply setting the PC to the reset vector address.

  * The 'listdelay' command now accepts a value of zero, indicating that
    list-skipping (jumping to a line in a list by keypress) is disabled.

  * The 'ctrlcombo' command now has a GUI item, allowing it to be changed
    from within the application.

  * Added 'Shift-Alt/Shift-Cmd s' keyboard shortcut, to enable continuous
    snapshot mode for each frame.  This is really only useful if you
    save snapshots in 1x mode; using it in high-resolution mode is
    not recommended.  Special thanks to SvOlli for the idea and code.

  * The minimum supported version for the OSX port is now OSX 10.7.
    Because of this, the 32-bit version is also discontinued, as 10.7
    supports 64-bit Intel only apps.

  * Updated internal ROM properties database to ROM-Hunter version 10
    (thanks go to RomHunter for his tireless research in this area).
    Related to this, updated the snapshot collection.

  * Updated included PNG library to latest stable version.


4.1.1 to 4.2: (October 28, 2014)

  * Text input from non-US keyboard layouts is now supported.  Note that
    all text in Stella is still ASCII-only, but at least it can now be
    entered using a native layout.

  * Related to the text input changes, the debugger Alt-combo shortcuts
    have been changed; they now use the same key but with Control instead
    of Alt (Control-F for frame advance, etc).

  * Controllers are now detected dynamically by Stella.  This means that
    you can plug/unplug joysticks/paddles/etc while Stella is running,
    and they will be added and removed automatically.  Also fixed is
    a bug whereby sometimes custom joystick mappings weren't being saved.

  * The 'cpurandom' option is now broken down by register type, so you
    can selectively enable/disable randomization for each one.  The
    default is to disable randomization for all registers.

  * Fixed 'MDM' scheme to trigger bankswitching on writes to hotspots
    (previously it only triggered on reads).  Also, the scheme has been
    modified as originally designed by E. Blink; hotspots are now in the
    range $800-$BFF instead of $800-$FFF.

  * The OSX app-icon now includes 32x32 and 16x16 versions, so 'small'
    icons will be viewable in 'Finder', 'Get Info', etc.

  * The Linux port now uses an app-icon; this seems to be needed for
    some window managers.


4.1 to 4.1.1: (September 14, 2014)

  * Re-added 'uipalette' option due to popular demand (of at least one
    person :)).

  * Fixed bug in Windows port where pressing 'Alt' key combos resulted in
    an annoying system beep.  Currently this is fixed by patching the SDL2
    library and including a modified version with Stella.


4.0 to 4.1: (September 1, 2014)

  * Improved 'DASH' bankswitching scheme support; there is now a debugger
    tab for changing banks and viewing internal cart RAM, and
    autodetection is now implemented.

  * Added 'MDM' (Menu Driven Megacart) bankswitch scheme as described on
    AtariAge and originally developed by Edwin Blink.

  * Improved snapshot viewing in the ROM launcher; snapshots are now
    scaled to the available space, and can better accommodate sizes
    other than those generated by Stella itself.

  * Improved support on multi-monitor systems.  Stella will now use the
    same monitor for fullscreen-windowed mode switches.  Special thanks
    to Magnus Lind for patches that added this functionality.

  * Removed the 'bank' command from the debugger prompt, as it only worked
    (inconsistently) with certain bankswitch types.  The bankswitch UI
    should now be used to query/set bank state.

  * Fixed bug in disassembly output; instructions at $F000 were never
    being highlighted during execution.

  * The UNIX configure script now supports newer versions of Hurd.
    Special thanks to Stephen Kitt for the patch.


3.9.3 to 4.0: (July 1, 2014)

  * Ported Stella to SDL2, which brings many new features.  Among the
    largest improvements is native hardware acceleration support for
    Windows (Direct3D) and Linux/OSX (OpenGL).  It is also now possible
    to port Stella to iOS and Android devices using OpenGLES.
    Hardware acceleration is now required, which means up-to-date drivers
    are needed.  Software rendering is still present, but is somewhat
    unoptimized and unsupported going forward.

  * Fullscreen video modes now use the desktop resolution.  Switching
    to fullscreen and back to windowed mode no longer rearranges icons
    on your desktop.

  * TIA TV effects are now available in all video modes, since hardware
    acceleration is a requirement.

  * Added a much more detailed view of cart extended RAM to a new
    debugger tab.  Special thanks to SpiceWare for this implementation.

  * Added preliminary support for 'DASH' bankswitching scheme by A. Davie.

  * The AtariVox and SaveKey controllers now have the ability in the
    debugger to completely erase the virtual EEPROM data.

  * Added 'savesnap' debugger prompt command, and also associated
    context menu item to the debugger TIA output area.  This saves the
    current TIA image to a PNG file.

  * Added 'hidecursor' commandline option, which allows to completely
    disable showing the mouse cursor (useful on systems that don't have
    a mouse).

  * Removed 'uipalette' option, as the original palette is no longer
    supported.

  * Updated included PNG library to latest stable version.


3.9.2 to 3.9.3: (January 20, 2014)

  * Added bankswitch schemes BF, BFSC, DF, DFSC and 4KSC, thanks to
    RevEng and CPUWIZ of AtariAge.

  * Updated ROM properties for several ROMs, thanks to Omegamatrix of
    AtariAge.

  * Fixed program crash when specifying a bankswitch type that Stella
    didn't recognize; an error message is now displayed.


3.9.1 to 3.9.2: (August 31, 2013)

  * Improved parsing of the DASM lst file for the debugger disassembly;
    it sometimes missed constant declarations.

  * Changed 'usemouse' argument from a true/false option to accept
    'always', 'analog' and 'never'.  This allows to use the mouse as a
    controller under more specific circumstances.  The default is
    'analog', which means the mouse is only used to emulate analog-like
    devices (paddles, trackball, etc).

  * Added ability to use bold fonts within the debugger window, which can
    be set with the 'dbg.fontstyle' commandline argument as well as in the
    debugger UI Settings dialog.  This is useful for those that find the
    current font too narrow.

  * Renamed 'debuggerres' argument to 'dbg.res'.  All future debugger-
    specific options will start with 'dbg.'.

  * The TIA 'zoom' area in the debugger now supports scrolling the
    mouse wheel (currently up/down only, as I don't have a sideways
    scrolling mouse to test with).


3.9 to 3.9.1: (August 21, 2013)

  * Note: because of TIA/6502 changes, the state file format has changed
          again, and old state files will not work with this release.

  * Several bugfixes and improvements to the debugger:
      - Improved display of debugger when using larger video modes.  There
        are now three font sizes, which are automatically selected when
        the debugger is sized accordingly.  When using larger fonts, the
        extra space is now used more efficiently.

      - Fixed bug in disassembly when the mirror used for the current
        PC didn't match the mirror for the current bank.  In this case,
        the disassembler became confused and didn't properly track the
        PC address.

      - Fixed bug in display of current TIA frame number in the UI;
        depending on how breakpoints were set, it was sometimes off by
        one.

      - Fixed RAM widget Search/Compare textboxes; entering any data and
        then pressing 'Enter' / clicking 'OK' locked the UI until exiting
        and re-entering the debugger.

      - Changed display for various TIA position counters to decimal
        (from hex) in the TIA tab.  Related to this, all data input
        widgets in the UI now have the ability to enter binary,
        decimal or hex values by using the proper leading character
        (\, #, $, respectively).

      - Added 'INTIM Clks' to the 'I/O' tab. which shows the number of
        clocks between each 'step' of the INTIM timer.

      - Added ability to modify 'tiadriven' commandline argument to the
        'TIA' tab, and 'ramrandom' to the 'I/O' tab.  These options were
        available for quite some time, but they weren't exposed in the UI.

      - Added 'cpurandom' commandline argument, and associated UI item
        to the 'I/O' tab.  This works similar to 'ramrandom', and
        randomizes the contents of the CPU registers on ROM startup.

      - Added 'uhex' debugger prompt command, which toggles all
        hexadecimal display between upper/lower case.  This setting is
        also saved in the settings file as argument 'dbg.uhex'.

      - Removed 'loadsym' command from the debugger prompt, since the
        DASM symbol file is always loaded anyway, making the command
        redundant.  Related to this, fixed loading symbols with
        ###.name convention; the leading number is now stripped.

      - Added support for DASM lst files (created with the -l option).
        For now, the contents are only partially used, to detect
        constants vs. symbolic addresses in the symbol file.  Eventually,
        further information from the lst file may be used.

      - The GRPx and PFx registers in the TIA output now show inactive
        background pixels as either blanked or with the underlying object
        colour, instead of always being black.   This gives a more accurate
        representation of how the registers are actually drawn onscreen.
        Thanks to Tjoppen of AtariAge for this idea and sample code.

      - The 'Source Address' locations for the CPU registers now show
        labels where appropriate.

  * Renamed 'Override properties' dialog (accessible from the ROM
    launcher by a right-mouse-button click) to 'Power-on options', with
    the following new options:
      - Set start-up state for both joysticks as well as console select/
        reset buttons.  Related to this, added 'holdjoy01' and 'holdjoy1'
        commandline arguments, and removed 'holdbutton0' argument.

      - The ability to load the ROM directly from this dialog, after
        changing any settings, and also to start in the debugger.

      - Added more detailed information as to how to use this
        functionality to the UI.

      - Buttons held down are reset approx. 0.5 seconds after starting
        the ROM, to simulate pressing and releasing the buttons on a
        real console.

  * Fixed bug when using event remapping; changes were being saved only
    when launching a ROM from the launcher, not in standalone mode.

  * Improved bankswitch autodetection for newer EF and EFSC ROMs
    generated by batari Basic, thanks to RevEng of AtariAge.

  * Added properties database info for "Princess Rescue" ROM.

  * For the Linux/UNIX port:
      - Fixed bug whereby a maximize button was always present in the
        window title bar.  Stella could not be expanded in this way,
        so the button was removed.

      - Added Startup notification protocol patch to the .desktop
        file from Dan Fandrich.

  * Updated included PNG library to latest stable version.


3.8.1 to 3.9: (June 27, 2013)

  * Greatly extended functionality of the debugger disassembly:
      - There is now a new tab which lists information specific to the
        cartridge bankswitching scheme in use.  This includes the ability
        to modify internal state even for esoteric ROMs which don't
        follow the standard layout of 4K per bank.

      - The debugger now generates DASM-compatible disassembled code,
        which can be saved to an external file.  This disassembly is
        based on both a static and runtime analysis, and is extremely
        accurate.  It also automatically differentiates between
        CODE/PGFX/GFX/DATA/ROW areas, whereas normal Distella
        only differentiates between CODE/GFX/ROW.  For now, only
        single-bank (4K and smaller) ROMs are supported; support for
        multi-bank ROMs will come in a future release.

      - The disassembly now recognizes various TIA/RIOT read/write
        mirrors, and marks them as such (for example, INPT4|$30 instead
        of INPT4 for address $3C).  Special thanks to Omegamatrix for
        sample code and idea for this feature.

      - ROMS less than 2K in size (so called 'Sub2K' ROMs) now show only
        the actual data in the binary.  This means, for example, that a
        256 byte ROM will show only 256 bytes in the disassembly, instead
        of padding duplicated data to 2K boundary.

      - Fixed bug when entering patched bytes; the current number base
        wasn't being used.

      - Fixed labelling in ROW directives; it wasn't accurately setting
        a label in the case where it occurred in the middle of the data.

      - Added a new dialog for changing Distella settings, located by
        right-clicking the disassembly code.

      - The commandline option 'dis.resolvedata' has been renamed to
        'dis.resolve', with new usage (see manual for further details).

  * Fixed regression in handling ZIP files (as compared to version 3.7.5)
    created with newer versions of the ZIP program.  Related to this, added
    better error messages for invalid/missing/unreadable ROM files.

  * Added 'snapname' commandline argument and associated UI item, for
    specifying whether snapshots should be saved using either the internal
    ROM database name or the actual ROM filename.  This feature was
    present in older releases of Stella, and due to popular demand it's
    now back again.  Related to this, added a new dialog specifically for
    the numerous snapshot-related items.

  * Fixed bug in Linux/OSX versions when starting Stella for the first
    time; it was previously creating mislabeled directories to store
    settings, snapshots, etc.

  * Fixed redundant "New console created" message when entering the same
    ROM multiple times from the ROM launcher.

  * Updated profile database for "BasketBall" ROMs; the joysticks are now
    swapped by default, which allows one and two-player games to work
    correctly.

  * SuperCharger/AR ROMs now ignore the 'ramrandom' setting, and start with
    RAM containing all zeroes.  This seems to fix issues with Dragonstomper
    always starting in exactly the same state.

  * Fixed issue when debugging CompuMate ROMs; keystrokes entered while
    debugging would be interpreted as typing on the CompuMate keyboard.

  * Changed colour of the 'current PC indicator' in the debugger to
    match the one used for line selection.  This makes it easier to
    see for those with problems seeing lighter colours.

  * Improved functionality of the various pop-up dialogs and context
    menus in the UI; they can now be navigated more fully by the keyboard
    and mouse.

  * Updated internal ROM properties database to ROM-Hunter version 9
    (thanks go to RomHunter for his tireless research in this area).
    Related to this, updated the snapshot collection.

  * Updated included PNG and ZLIB libraries to latest stable version.


3.8 to 3.8.1: (March 3, 2013)

  * Added support for TIA RSYNC writes, thanks to Omegamatrix of AtariAge.
    This allows the recently released "Extra Terrestrials" ROM to run, as
    well as improving emulation of "Fatal Run" and several other test ROMs.

  * Fixed typo in TIA HMOVE writes, thanks to Thomas Jentzsch.  This fixes
    the constant collision issues in "Kool-Aid Man", and several other
    homebrew ROMs.

  * Fixed sound issues on OSX PPC machines (all sound was in little-endian
    format, but PPC is big-endian).

  * The OSX DMG archive now contains proper modification dates.


3.7.5 to 3.8: (February 21, 2013)

  * Huge changes to the sound system:
      - The sound code now uses 16-bit signed samples instead of 8-bit
        unsigned samples, making it more compatible with a wider variety of
        systems.
      - Improved sound output for several ROMs, including "Space Rocks"
        (the 'heartbeat' sound can now be clearly heard).
      - The 'volume clipping' option has been removed, since in 16-bit
        mode it's no longer needed.
      - The 'Tia freq' option has been removed.
      - Selecting more common sample rates (other than 31400) now works
        much better, but there are still a few ROMS (like Quadrun) where
        31400Hz still works best.

  * Many changes to handling ZIP archives:
      - Files in multiple levels are now recognized.  This fixes issues
        in Windows where such files couldn't be loaded at all, and in all
        systems where ROMs with the same name (but in different
        directories) weren't being recognized.
      - ZIP contents are now handled more intelligently.  Archives
        containing only one ROM are automatically loaded, whereas those
        with multiple files are treated as directories.
      - Opening an archive from the commandline now works as in the UI,
        where opening a multi-ROM archive will pop up the UI and show the
        archive contents (as a directory).
      - The ZIP code behind the scenes is now much faster by making use
        of caching (the old code was actually from 1998!).
      - This new 'archive' infrastructure may eventually lead to 7-Zip
        support, as well as 'virtual' formats (such as showing the list
        of files for 2in1/4in1/8in1/etc within the UI).

  * Improved bankswitch autodetection for FA2 ROMs; 29K and 32K versions
    (meant f