Firmware for Ultimate Platforms

Firmware version 3.14d - for All Platforms: U2, U2+, U2+L, U64 and U64E2! - Dated 2026-03-01

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This version also includes an update for the WiFi modules (U2+L, U64 and U64E2). This update might fail the first time around, because of the way the firmware 'talks' to the modules has changed. Just run the updater again, skip the primary update and then update the ESP32.

It is highly recommended to update your Ultimate 64 Elite-II with this version after receiving it.

Once again, this release was only possible by spending countless hours of coding and debugging. If you appreciate the free additions and improvements to the Ultimate product, and you would like to contribute, consider leaving a small donation:

Version 3.14d has the following improvements over 3.12:

New Features:

Support multiple resolutions U64E2
Updated LED strip controller. Now supports WS2812 and APA102
Added support for USB (boot) mice into 1351 mouse emulation (U64 / U64E2 only)
Added support for PDsid (at least detection and maybe also 6580/8580 switch)

WiFi and Network Improvements:

Network stack configuration; fixes modem disconnects
Ethernet driver bugfix; fixes random TCP/IP stack corruptions
DNS Server configurable and Time settings reenabled on U64 I
Enabling / disabling DHCP now works (used to switch to 0.0.0.0)
Delays in socket polling set correctly for LWIP 2.1
Automatic network selection
WiFi: Do not connect to unknown public APs
Fixed UIChoiceBox for Authentication mode configuration (needed for open networks)
Split Rx and Tx buffers to WiFi module to avoid Tx starvation (fixes WiFi lockups)

HDMI Improvements:

Support multiple resolutions U64E2
1080p50 is now fully compliant (U64E2)
Fix for HDMI CTS 7.33a (both U64 and U64E2)

Modem Improvements:

ACIA compatibility improvements

Cartridge Emulation Improvements:

Pagefox CRT [ISSUE-492]
EAPI fix [ISSUE-495]
Automatic mirroring of cartridge ROM area (improves compatibility)
C64GS cartridge support

Web Interface Improvements:

Update Live Monitor
BASIC Editor, bug fixes and tokenizer improvements
Web SID/PRG/CRT player: drag&drop support

User Experience / Menu Improvements:

Global enable / disable for the speaker (U64E2).
Aesthetics in C64 Machine menu
Fix typo in Assembly64 help screen
Configuration menu overhaul; better grouping and general cleanup
Work done on color schemes
WiFi and Ethernet status showing and updating in config page
Show networks in file browser again
Allow viewing text files in Assembly 64
Allow copying files from Assembly 64

General Bugfixes:

Fixes race condition in UCI
Video mode update on U64 MK1 was broken, fixed
Fixes configuration items that were not stored properly
Memory timing issue fixed for U2+L and U64E2
Fix for Ethernet not starting correctly on U64E2
Avoid 'freeze' in ultimate app from interfering with TOD clock in CIA#1
Fixes Userport 9V power on U64E2
Fix RGB palette loading on U64E2
Fixes SocketDMA vulnerability [ISSUE 586]
Fix memory leak in Temp writer / REU writer in API endpoints.
Fix incorrect string length in telnet password response.
Updated CIA timing to fix drive loading. This fixes JiffyDOS on U64E2
Turn off turbo mode temporarily on reset to have PAL/NTSC detected properly. This allows JiffyDOS to work correctly with Turbo mode enabled.
Add delay to start tape when running .tap. This fixes some tape titles.
Fixed a memory leak in file copy function
Allow copying bigger files without USB crash (experimental)
Fix remote control over REST API for data streams
Fix overlay menu position on U64.
Re-enable speaker config for U64.
Updated SID register readback: Split SIDs can now be correctly detected
Show diamond character when selection uses reverse
Reset SoftIEC to partition 0 upon reset command
IEC drive reset now also resets partition 0 to correct path.
Fixed ACIA/IRQ support: ACIA always used NMI
Allow ACIA with C128 hardware type 1, subtype 2 crt
Turn on ACIA on again after it was prohibited by cart.

Firmware version 3.12a - for All Platforms: U2, U2+, U2+L, U64 and U64E2! - Dated 2025-06-19

Click here to download

It is highly recommended to update your Ultimate 64 Elite-II with this version after receiving it.

A more elaborate change list / release notes follows soonish.

Firmware version 3.11a - for U2+L - Dated 2024-05-10

Click here to download This version adds WiFi support for the Ultimate II+L.
Additions:

WiFi support - Now that the WiFi modules for the U2+L are available, you will need this firmware to enable it. In this zip there are two files; the firmware update for the cartridge itself (.u2l) file and the firmware file for the ESP WiFi module (.esp). They have to be applied in this order.
Ethernet fix - Improves compatibility with some switches and routers. The LAN should now work with these.
Garbled characters fix. - On some machines, especially on NTSC machines, the 3.11 firmware gave some timing issues. This build should fix that.

Due to "life" (e.g. house renovation) there has not been any time for testing this firmware for other hardware platforms. Will come soon.

Firmware version 3.11 / Core 1.43 - Dated 2023-12-28

Click here to download
Additions:

This version adds WiFi support for the Ultimate 64 and Ultimate 64 Elite. Please read the manual on how to set up the ESP32 module. https://1541u-documentation.readthedocs.io/en/latest/howto/wifi.html
Assembly 64 integration. Many users use the offline version of the great Assembly 64 online database, by running Fredrik's tool to copy the content into folders onto a USB stick. Now, the Ultimate is the first embedded ever system that integrates access to this online database! You can now simply download and play titles directly from the internet on your Ultimate device. Please read the manual about this here: https://1541u-documentation.readthedocs.io/en/latest/howto/assembly.html
The Ultimate now supports a basic http daemon; also known as webserver. This allows some simple files to be served from the Ultimate. This server also implements a ReSTful API, which allows an external device to control the Ultimate with standard web URLs. Read up on the API here: https://1541u-documentation.readthedocs.io/en/latest/api/api_calls.html
JiffyDOS support for the built-in SoftwareIEC drive. This is a first step to make the internal drive more usable. More effort needs to be done to make the command set more compatible with CMD.
On the Ultimate 64 it is now possible to isolate the serial bus from the computer, which allows the Ultimate 64 to be used as external drives. Look for "Serial Bus Mode" in the "Ultimate 64 Specific Settings".

Fixes:
Various small fixes, such as the telnet session closing upon mount, configuration of the cartrdiges that serve VIC data from external ROM, quite a few fixes in the emulated printer, configurable page margins, ... and so on.

Firmware version 3.10j / Core 1.42 - Dated 2023-06-21

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This release now also includes the Ultimate-II+L version of the firmware!
The release notes can be found here: Change Log
Installation and User Manual V3.10i/j

Firmware version 3.10a / Core 1.41 - Dated 2021-09-11

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This release fixes some (new and existing) issues in the 3.10 release. If you are not on 3.10 yet, please read the manual before installing 3.10a, since the changes from 3.9 and earlier are significant.

Firmware version 3.10 / Core 1.41 - Dated: 2021-07-24

Click here to download
This release has again some significant changes and improvements over 1.37 / 3.9. Please read the manual before installing 3.10.
Installation and User Manual V3.10

The older firmware page from this website, can be found here.
All binaries can be found on GitHub, https://github.com/GideonZ/ultimate_releases.