In 2012, Sebastian Bartkowicz (Candle) 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 the firmware 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 3
- Number of BIOS configuration profiles increased from three to four
- Massively faster and more powerful loader search facility
- Loader’s built-in FAT DOS now supports subdirectories
- Loader now remembers the last accessed FAT folder
- Loader scripts may include paths
- Loader can now open the location of any already mounted image
- Usability improvements to the loader and BIOS setup menu
- Optional synthetic ‘IO sound’ with ATRs and hard disk partitions
- Improved loader compatibility
- Auto-booting banked cartridge conversions on SIDE/SIDE2
- All hardware-specific HDD functionality moved to plugins
- Several important bug fixes
Important: If you wish your existing configuration profiles to be preserved, be sure to select profile 1 before updating the firmware.
Note: Owners of Ultimate 1MB with the original v.1 CPLD code from Candle’s first run of boards 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, it is guaranteed to be compatible with the new firmware.
Loader Quick Reference
Plugin Source Code
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.