Current MPE, A8PicoCart and A8PicoDuo support

Current cartridge support and standalone VMs from Mean Hamster Software. Solo and Duo factory bundles updated October 25, 2026 to merged firmware 1.6.35. Other download versions are unchanged.

• A8PicoCart-Support.zip: firmware 1.6.35 factory image, verified full-16-MB eraser, preloaded software and installation/license README.
• A8PicoDuo-Support.zip: matching 1.6.35 Library A/B factory images, verified full-16-MB eraser, preloaded software and installation/license README.
• Teensy.Support.Package.zip: official stock TeensyROM+ 0.9 and matched 1.4.12 MPE.TRH; the existing 1.4.11 HamsterOS, six apps, dictionary and VMS/MPE registration are unchanged. Install MPE.TRH through the stock menu, then fully power-cycle.
• KFF2-Support.zip: 2.29 updater and matched 1.4.11 HamsterOS/apps. Existing folder layout and notices are retained; the updater filename is KungFuFlash_v2.29.upd.
• DOOMVM_C64.ZIP: the existing portable Teensy/KFF2 DoomVM download under its new name, with the licensed Doom 1.9 shareware episode. Internal files are unchanged.
• NESVM_C64.zip: the existing portable Teensy/KFF2 NESVM download under its new name. Internal files are unchanged.
• GBVM_C64.zip: portable Teensy/KFF2 Game Boy and Game Boy Color player, retaining the root GBVM.MPE and VMS/GBVM library/save layout. Supply your own ROMs.
• GGVM_C64.zip and Tritari_C64.zip: portable C64 players for Teensy/KFF2, with the existing root-player and VMS library convention. Supply your own ROMs.
• Tritari_A8.zip and GGVM_A8.zip: standalone Atari cartridge players using their existing SD paths. Supply your own ROMs.
• DOOMVM_A8.zip and DOOMVM_A8_DUO.zip: separate Solo and Duo Doom packages with the shareware episode, retaining GAMES/DOOM.MPE and GAMES/DoomDuo.MPE respectively.

These thirteen ZIPs are the only uploaded downloads. Existing C64 archive layouts are retained. Both Atari support downloads contain the qualified factory and eraser UF2 files, installation directions, component notices and written source offers. No source archives, loose source files or separate checksum downloads are added. Required component notices and written source offers are preserved.

A8 factory setup: use factory images for initial setup or an intentional complete reset. Back up an existing cartridge first. Follow the erase/install steps on every Pico: once for Solo and separately on both Duo boards. The archive README supplies the matching filenames. Routine updates use Power Engine's matching updater and packages to preserve user files.

Firmware 1.6.35 combines the Type-63 cartridge cache improvement and the Duo startup fix. Native Monkey Island is not included. The next Power Engine application is being prepared separately; these downloads do not update it. The merged firmware has software/model and filesystem-readback qualification; compatibility with every physical Atari remains unconfirmed.

A8PicoDuo factory install — erase BOTH Picos first

This erases all firmware, games, settings and saves. Back up anything you want to keep.

The compact factory images skip unused storage. Old data can remain there unless you first erase the entire 16 MB chip. Use the included eraser on both Picos, not just Library A.

1. Remove the cartridge from the Atari and disconnect Atari power. Use USB only during installation.
2. Hold BOOTSEL while connecting Library A / U1 to your PC. Release BOOTSEL when RPI-RP2 appears.
3. Copy 01-ERASE-ALL-16MiB-Verified.uf2 to RPI-RP2. Keep USB connected and wait for RPI-RP2 to return. The end of the file copy is not erase completion: the tool erases and verifies the full 16 MB before returning the drive.
4. Only after RPI-RP2 returns, copy A8PicoDuo-A-Factory-1.6.35.uf2. Wait for programming to finish, then disconnect USB.
5. Repeat the erase/wait/install steps on Library B / U2, using A8PicoDuo-B-Factory-1.6.35.uf2 after the eraser finishes.

Both Picos must receive their matching 1.6.35 images. Fully power off/on after installation. Do not copy the eraser and factory image together. If RPI-RP2 does not return after erasing, stop rather than assuming it finished.

This erase step is for a factory installation or deliberate complete reset. Routine FIRMWARE.UPD updates preserve user files and do not require erasing.

Included eraser — license notices

LICENSE-Recovery.txt

MIT License

Copyright (c) 2026 Mean Hamster Software

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Recovery notice: running this tool ERASES ALL firmware, games and saves on one
16MiB Pico. Its sole purpose is destructive recovery before a fresh install.
Pico SDK and TinyUSB retain their separately supplied upstream licenses.

LICENSE-Pico-SDK.txt

Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
   disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
   disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

LICENSE-TinyUSB.txt

The MIT License (MIT)

Copyright (c) 2018, hathach (tinyusb.org)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

For ordinary package/SD updates, preserve your libraries, settings and saves. Software qualification and file readback do not establish physical cartridge or complete-game acceptance. The retained H24 acceptance records document that earlier updater; they do not claim physical acceptance of KFF2 2.29.

Installation and package guide · Power Engine for 8-Bits