Atari800MacX saw an update recently. After several months without updates, it now sits at version 4.4.0 and can be found in the Box File Widget or their homepage. Let’s check out the changes.

  • Added support for 512 byte sector SpartaDos X ATR disk images.
Bugs Fixed:
  • Fixed bug where erroneously long frame sleeps caused emulator to lock up.
  • Fixed issue with window miniaturization buttons.
  • Fixed issues with some special characters not being able to be entered in the emulator as well as some international key sequences.
  • Fixed issue with super/subscript modes in Epson Printer emulation.
  • Fixed issue with R: network emulation and incoming connections, BBS Software will now work.

Stella the 2600 Emulator Updated






Stella, the Atari 2600 emulator for Mac OSX, now sits at version 3.3 and you can find it in the Box File Widget or from their homepage. Don’t forget that there are 2 versions, a 32 bit and a 64 bit version. The 64 bit version is for Snow Leopard users only. Let’s check out the changes because there are lots of them this time.

  • Added the following Distella ‘directives’, which are used to override and specifically tell the debugger how to treat address space (CODE, GFX, PGFX, DATA, ROW). See the debugger documentation for more information.
  • Disassembly from the debugger is now tracked by the emulation core, and accented by the built-in Distella code. Basically, the emulation core knows when an address is referenced as code, making for very accurate disassembled output. Related to this, the emulation core now tracks accesses to GRPx and PFx registers, automatically marking the addresses as GFX or PGFX sections. This will be improved in future releases, as there are many ways to store data in the graphics registers.
  • Improved output of graphics output in the disassembler, by marking such addresses with a bitmap of the data they represent. This allows player graphics (GFX directive) and playfield graphics (PGFX directive) to really stand out in the disassembly. Related to this, added ability to edit such graphics in either binary or hexidecimal.
  • Added preliminary support for Distella configuration files. Much more work is required in this area, since Stella now contains directives that don’t yet exist in the standalone Distella program. Configuration files are automatically loaded, and debugger commands now exist to load and save configuration directives directly from the debugger.
  • Added the following commands to the debugger prompt:
    • clearconfig, listconfig, loadconfig, saveconfig
      (used for Distella configuration files)
    • code, data, gfx, pgfx, row
      (directives used to override automatic disassembly types)
    • jump (jumps to a specific address in the disassembly)
    • type (gives detailed info for disassembly type of an address)

  • The debugger prompt commands ‘trap’, ‘trapread’ and ‘trapwrite’ now accept a range of addresses as well as a single address.
  • Added ‘data source’ address output for the CPU SP/A/X/Y registers. This is useful for quickly seeing what an operand address resolves into with various load commands.
  • Many commands in the debugger prompt are now case-insensitive; further improvements will be made in future releases.
  • Many improvements to the built-in Distella disassembler. When passing a relative branch or jump, data is now disassembled as code only if the emulation core hasn’t detected it as data. Such ‘preliminary’ code is marked with a ‘*’ in the disassembler, indicating that it is tentative code, and hasn’t actually been executed yet. This allows to quickly see possible code paths, and at the same time eliminate disassembly of addresses that are never used as code sections.
  • Program counter/instruction addresses can now be toggled in the disassembly.
  • Disassembled instructions involving relative branches now show only one byte for the operand, not two bytes.
  • Fixed bug in several text input fields, whereby binary data couldn’t be input (a ‘\’ was required, but the character was blocked).
  • Fixed issues with PAL ROMs on screenmodes smaller than a PAL ROM would require. In this case, the image is centered and clipped to the screen resolution. This prevents the message “PAL ROM not supported” from appearing.
  • Fixed bug in fullscreen OpenGL mode when using ATI video cards; the desktop background was ‘bleeding through’, resulting in a very annoying flickering.
  • Fixed crashes when opening windows larger than the desktop resolution in fullscreen mode; this is now allowed only in windowed mode.
  • Application window centering now also works when switching between video modes, not just when starting the application.
  • Added support for building a Windows version compatible with Windows 98 and 2000 (compiled with Visual Studio 2005). Testing is very limited, since I no longer have access to these systems.
  • Fixed build issues for Innosetup in Windows XP.
  • Fixed bug in OSX version where the name of the application wasn’t being shown in Activity Monitor.
  • State files from older versions will no longer work in this release, because of the extensive changes to the debugger and disassembler.

Stella 3.0 for Mac OSX

The Atari 2600 emulator for the mac has been recently updated. Scope the links and the release notes.

Home Page


(Release notes from the txt file.)

* Huge updates to the TIA emulation system.  Illegal HMOVEs are now
handled correctly, resulting in improvements to many ROMs (thanks
to Wilbert Pol for many ideas and code for these improvements).  All
HMOVE emulation ‘cheats’ were removed; the emulation is now cycle-exact
in this area.

* Improved emulation of the Cosmic Ark ‘starfield effect’, also used in
Stay Frosty; the emulation now looks very accurate.

* Many improvements to the normal TIA rendering code, fixing problems
when disabling certain graphical objects (certain objects were
being misdrawn when others were enabled/disabled).

* Improved TIA collision handling in the non-displayable area of the
screen; this fixes problems in RAMRacer ROM.

* Improved TIA redraw problems/graphical garbage when ROMs generate
many more scanlines than a real TV would allow; this fixes problems
in Q-Bert and the recent Playaround demo.

* Added ‘Fixed Debug Colors’ option similar to the no$26k emulator.
This allows each graphical object to be drawn in a fixed color,
more clearly showing how the objects interact.  HMOVE blanks are
also shown in a different color.  The TIA now emulates a 7-color
register model, allowing even shared objects to show different
colors.  This is toggled with the ‘Alt Comma’ key.

* Related to ‘Fixed Debug Colors’, HMOVE blanks can now toggled during
TIA display with the ‘Alt-m’ key.

* Added rewind functionality to the debugger, where states are saved
after each step/trace/scanline/frame advance.  Pressing ‘Alt-r’ or
clicking the new rewind button will undo up to 100 previous

* Added ‘electron beam indicator’ to the debugger TIA output.  Basically,
this is a visual pointer indicating the position of the electron gun
when scanning the display.

* Added ability to completely disable fullscreen mode, which fixes
problems for some people where fullscreen mode was being entered
even if it wasn’t enabled.

* Added ‘-joyallow4’ commandline argument and associated UI item to
allow all 4 directions to be pressed simultaneously on a joystick.

* Improvements made to the ROM launcher: the backspace key now goes
to the parent directory (this key can be remapped), and previously
selected directories are now automatically selected.

* Added support for 2IN1 bankswitching scheme, where two ROMs are
present in one binary.  Currently supported are 2, 4, 8, and 16K

* Added bankswitch support for the 6K version of Starpath/Supercharger
ROMS.  This allows the 6K version of Cubis to run.

* Updated bankswitching schemes FASC and MB; they are now known as
FA and F0, respectively.  This naming brings Stella in line with
other emulators and programming utilities.

* Fixed editing of cheats in the Cheat Dialog; the old cheat wasn’t
being removed.

CHEERS to the InterWeb!