StellaDS Phoenix Edition

StellaDS Phoenix Edition
General
Author	Dave Bernazzani (wavemotion)
Type	Console
Version	6.7
License	Mixed
Last Updated	2023/06/24
Links
Download
Website
Source

StellaDS is an Atari 2600 console emulator for the DS/DSi, based on AlekMaul's StellaDS.

This is the Phoenix Edition with improvements of speed, compatibility and accuracy to the emulation on the DSi. It also added new features such as instruction manuals and high score support.

Features

• High level of compatibility to make games playable. Most games you remember fondly run full speed on a DSi in native 133MHz mode.
• Full console emulation including Reset, Select, Difficulty Switches, TV Type.
• Wide range of controllers including joystick, paddles, driving controller, booster grip, keypad, Genesis 2-button and more.
• Savekey Support with backing 32K EEPROM.
• FA2 and Cherity supported with backing EEPROM support.
• Most popular bankswitching is supported up to 128K/256K BF/EF/DF/SB and 512K 3E and 3F schemes with up to 32K of RAM.
• DPC+ Arm-Assisted games supported.
• CDF/CDFJ/CDFJ+ Arm-Assisted games supported.
• High score support with up to 10 scores for each game.
• Manuals for more than 100 of the common games included.
• Keypad overlay for Star Raiders.
• Frame Blending to help smooth out flicker.

Installation

Note: To use this emulator, you must use compatibles rom with a26/bin format.

DIDL patch the StellaDS.nds file depending on the flash card (if it does not have auto-patching).

Copy it into a directory of your flash/(micro)SD/MMC card.

Put the a26/bin files where you want on your flashcard. If you are using Twilight Menu++, you may need to rename the .bin to .a26 in order to use.

User guide

When the emulator starts, click on the cartridge slot to choose a file.

Use Up/Down to select a file, then use A to load it.

Supported ROMS

See Comatiblity.txt for the list of the supported ROMS.

Generally these are going to be NTSC No-Intro roms or ROMHUNTER roms (mostly developed for American market in the early days of video games).

PAL roms (that were later ported for Europe market) may cut off at the bottom of the screen and may not run at the right speed.

In other words while PAL is supported, you are generally going to get the most genuine Atari 2600 experience with NTSC roms.

Configuration

The gear icon on the main screen allows you to set a number of configuration parameters related specifically to the game you are running. In addition to the parameters shown, the difficulty switches (Left/Right A/B) are also saved on a per-game basis.

If you change any configuration settings, you really should re-load the game after saving out your configuration - some settings such as Bank Switching and NTSC vs PAL are only applied when the game is first loaded.

Here is a description of the configuration items you can adjust. Be sure to press the START button to save out your configuration after making changes:

• Controller - Most games use the Left-Joystick but you can change this.
• Bankswitch - The system tries to auto-detect the correct bankswitching scheme.
• Frame Blend - Normal is fastest. Flicker free is slowest but blends frames. You can also try Flicker Reduce Background/Black which is mid-ground.
• TV Type - NTSC vs PAL. Reload your game after saving this setting.
• Sound - Normally ON. Can be turned OFF which will render screen faster.
• ABXY Button - Default to FIRE button but you can change this.
• HBLANK Zero - Whether system clears pixels on horizontal blanks. Turn off at your own risk (it will speed up emulation which helps with older DS-LITE).
• VBLANK Zero - Whether system clears pixels on vertical blanks. Turn off at your own risk (it will speed up emulation which helps with older DS-LITE).
• Analog Sens - Default is 10 (1.0x speed). You can ajust how the paddle emulation responds.
• Start Scanline - Starting Scanline setting. When the TV first starts output of scanlines.
• Num Scanlines - Number of scanlines to display. Don't touch if you don't understand this.
• Offset/Scale - You can ajust the screen scaling and offset positions for the game.

Controls

D-Pad - Joystick

A/B/Y - Fire button

Select - Atari Select switch

Start - Atari Reset switch

X - Show FPS (Frames per Second)

L - Toggle Full Speed (no trottle to 60FPS)

R+D-Pad - Shift display offset in the D-PAD direction

L+D-Pad - Change Scaling of the Y-Screen (Up/Down scaling only)

L+R+A - Swap LCD top/bottom

Use Stylus on buttons for other actions on bottom screen.

Screenshots

Compatibility

For the older DS-LITE and DS-PHAT, many of the simple 8k, 4k and 2k games will play perfectly. More sophisticated bank-switching schemes really require the DSi for the best experience.

If you're a fan of classic emulators on the DS/DSi, a DSi XL (USA) or LL (Japan) version is strongly recommended. Or a 2DS/3DS if you can get homebrews to run on those. The reason is that the original DSi has a fast LCD fade and as such some of the games will be a little hard to see or appear to flicker due to the way the original Atari game is coded. For a real TV or a slow LCD fade, this looks much better.

StellaDS includes an option to reduce the flicker - in configuration you can turn on Blending (recommend try Half Blend Mode as it's the least CPU intensive). This comes at a performance pentaly - for many games, the DSi can handle that penalty. For the ARM-Assisted games (DPC+, CDF/CDFJ/CDFJ+) that penalty will be too great which is why the full gammut of Atari games will always render best on an XL/LL screen.

Known issues

• Any ARM-Assisted games are generally complex enough that you will need a DSi running at the 2X CPU speed (via Unlaunch or Twilight Menu++) to get a good experience from it.
• CDF/CDFJ/CDFJ+ games are supported but the music fetchers (Draconian and Mappy) will not play properly so those games will have missing sounds. Otherwise the games will run fine on the DSi or better.
• Pitfall II DPC support is incomplete and the background music will not play correctly (game is otherwise fine to play).
• Cherity music fetchers are incomplete and the background music will not play correctly (game is otherwise fine to play).
• Stay Frosty 2 DPC+ music fetchers are very rough and the background music sounds terrible - so it's turned off by default (game is otherwise fine to play).
• Game filenames can be no longer than 168 characters including the extension. Rename to shorter if needed.
• No more than 1200 files can be shown in a directory. You can break up your games into multiple directories if needed.
• The original DS-Lite and DS-Phat are running at half the speed (67MHz vs 134MHz) of the DSi/DSi-XL and as such you will find that only a subset of games run at full speed. *Fortunately many of the best games will run fine - Space Invaders, Missile Command, Asteroids, Yars Revenge, Adventure, Phoenix, Chopper Command, Megamania, Pitfall!, Cosmic Ark, Demon Attack and lots more will be at your fingertips.

Changelog

V6.7 2023/06/24

• Fix for Sword of Surtr so it runs correctly.
• Hold L+R shoulder buttons for ~1 second to take a snapshot of the screen (written to SD card)
• DSi now defaults to the 'Accurate' BUS MODE for maximum compatibility.
• Improved data bus handling for undriven pins in Tia::Peek() for improved compatibility.
• A few more tweaks to a few more games to make them as accurate as possible.

V6.6b 2023/06/21

• DSi now defaults to the 'Accurate' BUS MODE for maximum compatibility.
• Improved data bus handling for undriven pins in Tia::Peek() for improved compatibility.
• A few more tweaks to a few more games to make them as accurate as possible.

V6.6 2023/06/20

• Fix for Meltdown prototype so it doesn't crash.
• Fix for Pleiades to fix graphical glitches.
• Fix for Atom Smasher prototype so it doesn't crash on start (wrong bank scheme detected).
• Fix for E7 banking so it handles 8K, 12K and 16K roms.
• Fix for Flash Gordon to eliminate graphical glitches.
• Fix for Elf Adventure prototype so it runs.
• Fix for Star Gunner so it doesn't glitch.
• Fix for Warlords graphical glitches.
• Fix for Worm War I graphical glitches.
• Fix for A-Star not starting.
• Fix for Hugo Hunt graphical glitches.
• Improved random() generator for more robust RAM clear / handling on startup and added config to either randomize RAM or clear it at start.
• Added new option to use the 'Compatible' BUS driver which will handles things like invalid reads and drives unused TIA bits (a few games rely on this - but it does slow down emulation slightly).

V6.5 2022/12/21

• Polished release - a few more tweaks, a few more optimizations and everything is running as fast science allows on the DS/DSi.
• Removed "ghost read" and "ghost writes" on the 6502 emulation for a bit more speed.
• Use of gcc "likely/unlikely" in a few key spots to help the compiler optimize.

V6.4 2022/12/16

• Reduced stack memory so we don't crash when first creating a Savekey EE file.
• Improved 6502 handling to localize the PC for a bit of a performance boost.
• Added the 3E+ banking scheme.
• New global palette and sound options on the Configuration Menu page 2 (use L/R keys).
• Other small improvements as time permitted.

V6.3 2022/12/11

• Improved performance across the board. More games play at the right speed even on the older DS-Lite/Phat.
• New QuadTari support - for now it's just Dual Joysticks + SaveKey which is useful for games like Robotwar.

V6.2 2022/12/05

• New WAVE DIRECT sound handling for fast-fetching music. Draconian, Mappy, Stay Frosty 2, Stella's Stocking, Pitfall II and Quadrun have much improved sound.
• New palette options to tweak the colors to your liking.
• Memory re-org for a bit more speed but also to recover some valuable resources so more features can be added in the future.
• Added a 2nd page (not yet populated) for possible future options. This requires a new configuration file format - your old one will be reset. Sorry!
• Fixed CDFJ+ fetchers causing problems (including incorrect handling of SaveKey).
• Other small improvements as time permitted.

V6.1 2022/12/01

• CDFJ+ games are now supported up to 256K of ROM and 32K of RAM. Turbo Arcade is playable but isn't yet full speed.
• More speedup in ARM Thumb processing.
• New Screen Pan Up and Pan Down handling - this can be mapped to any DS button (XYAB) to help with games that use more than 192 pixel lines (really useful for CDFJ games from Champ Games).

V6.0 2022/11/27

• CDF/CDFJ games are now supported (but not CDFJ+)
• Big speedup in ARM Thumb processing to render all DPC+ games full-speed on the DSi or above.

V5.9 2022/11/21

• Minor fixes for some games to render them more accurately including the new Chaotic Grill homebrew.
• Improved ARM Thumbulator for another frame of performance.
• Minor cleanups and optimizations across the board.

V5.8 2022/10/21

• Fixed colors in Medieval Mayhem (and a few other games).
• Fixed stars to show properly in Stay Frosty and Rabbit Transit.
• Streamlined DPC+ so Space Rocks and Stay Frosty 2 are full speed.
• Minor cleanups and optmizations across the board.

V5.7 2022/10/18

• Fixed Sword of Surtr so it plays properly.
• Added TWIN STICK controller so games like Rail Slider are playable!
• More DPC+ optimizations... Space Rocks is almost full speed!

V5.6 2022/10/14

• Massive speedup improvement for DPC+ games. Most play full speed on the DSi.
• Fixed graphical glitches on Space Rocks homebrew.
• Other cleanups and optimizations across the board to shine things up.

V5.5 2022/10/12

• Added DPC+ with ARM Thumbulator to provide some preliminary support for ARM-assisted games.
• Improved execution speed of the emulator and improved the frame blending algorithm.

V5.4 2022/10/07

• Added DF bank switching scheme (missed when DFSC was added).
• New core execution loop that gives us another 2 frames of performance.
• Optimized F4 driver to make some of the 32K games playable on DS-Lite.
• Cleanup across the board.

V5.3 2022/10/03

• Added Chetiry (CTY) bank switching scheme with EEPROM support (but no music fetchers).
• Improved memory handling across the board for another frame of performance.
• Fixed SP+ so it runs properly again.
• Improved driver for Midnight Magic and Realsports Tennis so both now run at 60FPS!

V5.2 2022/09/30

• Fixed goof in F6, F4 and related F6SC and F4SC drivers!
• Another frame of increased performance
• More accurate AR cart handling for Supercharger games
• V5.2a: 3E and related fix

V5.1 2022/09/29

• Improved all bankswitching for more speed and greater copatibility.
• New F6 driver for DS-LITE to support 16K games - many at full speed!
• Cleanups across the board.

V5.0 2022/09/27

• Added new bankswitching scheme: X07 (Stella's Stocking).
• Improved 4K/2K driver to squeese out a couple more frames of performance.
• New special F8 driver to support more 8K games on the DS-Lite.
• Lots of cleanup across the board in the database to make more games playable.
• Updated to 5.0c with another frame of improvement for 4K and 8K games!

V4.9 2022/09/18

• Added new bankswitching schemes: TVBOY, UASW and 0840 (Econobanking).
• Fixed UA bankswitching scheme to allow more games to run.

V4.8 2022/09/11

• Fixed Super Bank (SB) scheme.

V4.7 2022/03/24

• Added per-game configuration settings.
• Fixed 3E/3F and UA bankswitching schemes.

V4.6 2022/03/20

• Added SaveKey support - standard games will have a virtual SaveKey in the right controller jack and will be auto-backed to a 32K /data/StellaDS.EE file.
• Added EF, EFSC, DFSC and SB (SuperBank) support for games as large as 256K!

V4.5 2021/11/05

• New sound output core - no more zingers.

V4.4 2021/08/22

• Minor cleanups across the board. Improved AR cart speed by ~1FPS.
• Added horizontal stretch - use the Left Shoulder + L/R D-Pad.
• The Y button is now auto-fire.

V4.3 2021/08/09

• Massive overhaul of the non-bank-switched engine so now the older DS-Lite and DS-Phat will run many games at full speed.

V4.2 2021/08/02

• New overlay graphic for Star Raiders (plus manual).
• A half dozen odd games got their controllers straightened out.
• About 100 graphical tweaks for various games to make them look as good as possible.

V4.1 2021/07/28

• Found another 1-2% speed up in TIA rendering.
• Bumper Bash now plays correctly (you can use the shoulder buttons too).
• Kool-Aid-Man now plays correctly.
• Meltdown graphics improvements (but not fixed... but playable).
• Alpha Beam, Big Bird and Cookie Monster games all work with joystick controls now.

V4.0 2021/07/24

• Found another 3-5% speed up in TIA rendering! Official Frogger now at 60FPS.
• Press and hold L+R+A to swap LCD screens.
• Other minor cleanups and polish.

Release notes.

Credits

Thanks to:

• Bradford W. Mott for Stella.
• Alekmaul for porting Stella to the DS.
• Robz for Twilight-Menu++ which rekindled emulation on the classic handheld.

External links

• GitHub - https://github.com/wavemotion-dave/StellaDS
• GBAtemp - https://gbatemp.net/threads/stella-ds-improved.577691