In 2012, Sebastian Bartkowicz (Candle O’Sin) asked me to write a PBI BIOS to for Ultimate 1MB. During the months that followed, Candle thought of more and more things to add (such as the ability to read and write disk images mounted in the FAT partition of the CF card), and after weeks of coding and debugging, I had produced something approaching a final version.
In 2015, a desire to significantly broaden the functionality of Ultimate 1MB and overcome some of the limitations of the PBI BIOS led me to completely re-write every firmware component and produce a new main BIOS, PBI BIOS and XEX loader.
- A PBI implementation of Matthias Reichl’s High-Speed SIO code which does not require OS patching and which works with external cartridges
- The ability to set the system date and time from inside the BIOS setup utility
- Expanded PBI BIOS settings on a dedicated menu page
- System information page showing CPU type, audio and video hardware, and more
- User-selectable BIOS hotkeys
- Configuration profiles
- BIOS plugin API for user-defined external device control
- New, faster XEX loader supporting multiple FAT partitions, APT partition mounting, fast recursive searching and built-in FAT DOS
- Dedicated High-Speed SIO menu
- SIO2BT support (at up to 56kb/s) and high-speed SIO for PCLink and other serial devices
- Built-in CIO “Z:” RTC device handler
- Rapidus plug-in and support for PBI BIOS extensions in fast linear 65C816 RAM
New to Version 4.2
- SIDE3 Loader-style menu design
- Fixed Sophia 2 plugin
- Fixed JED version reporting
Important: Owners of Ultimate 1MB with the original v.1 CPLD code from Candle’s first run of boards (with glossy black PCB and requiring current limiting resisitors on the MMU cable) must ensure that they update to the current JED prior to installing the new BIOS, otherwise they risk bricking the device. Boards with the PBI feature (including all manufactured by Lotharek and those from Candle’s second run) will safely run the new BIOS without modification. If your U1MB has a white PCB or was purchased new from a commercial vendor since 2013, it is guaranteed to be compatible with the new firmware.
Note: this JED still reports as version 1 in the BIOS, and it’s HIGHLY UNLIKEY that you need to update any but the very oldest U1MB boards.
Loader Quick Reference
Plugin Source Code
Ultimate 1MB Links
Please lend your support to Lotharek at lotharek.pl. Thanks to him, Ultimate 1MB and other excellent Atari 8-bit upgrades are always available for convenient online purchase.
Licensing and Donations
In light of the fact that firmware licensing revenue is modest and that updates are offered for free to the end user, donations are welcomed and appreciated. Indeed, it has been my mission to facilitate easy and safe firmware updates, and regular in-the-field upgrades are encouraged to ensure that devices remain up to date and bug fixes are delivered in a timely manner.