In 2012, Sebastian Bartkowicz (Candle) asked me if I could write a BIOS to realize the PBI hard disk functionality he was developing for the 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, we had something approaching a final version.
In 2015, a desire to significantly broaden the functionality of Ultimate 1MB and correct some problems with the PBI BIOS led me to completely re-write the the firmware for the device, including the 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 2
- Number of configuration profiles increased from two to three
- Greatly increased XEX loading speed
- Better VBXE integration
- Numerous usability improvements to the loader and BIOS setup menu
- Better control of internal BASIC state
- Improved compatibility with SD/CF adapters
- Several critical bug fixes
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.
Plugin Source Code
Licensing and Donations
In light of the fact firmware licensing revenue is modest and updates are offered for free to the end user via this website, donations are welcomed and appreciated. Indeed, it has been my mission to facilitate easy and safe firmware updates, and in-field upgrades are encouraged to ensure that devices remain up to date and bug fixes are delivered in a timely manner.