1541 Ultimate II (Plus ) Firmware - markusC64/1541ultimate2 GitHub Wiki

Welcome to the 1541ultimate2 wiki!

Update Instructions:

Short for 1541 Ultimate II:

Copy update.bin to an SD-Card in order to update from firmware 2.x to another 2.y. Powercycle your C64 and the firmware'll install.
Use update.bin from official firmware relase to update a 1541 U2 to firmware 3.0 if and only if you are running firmware 2.x. This file is contained in firmware 3.0 only. To my knowledge, newer firmware versions will not contain it any more. https://github.com/markusC64/1541ultimate2/releases/tag/v3.0
Use *.u2u to update from Firmware 3.x to any other 3.x. In the official release, that file is usually named "update.u2u", in unoffiical releases the filename might refer to the verson. In any case, there is no need to rename it.
Use revert.u2u from 3.0 final release to downgrade to firmware 2.6k. From that firmware, you can update to any other 2.x firmware.

Note: With firmware 3.x, you have to select an ".u2u"-File in the filebrowser to start the update. It will not start automatically.

Short for 1541 Ultimate II Plus: Fur the 1541 U2 Plus, .u2p files are used instead of .u2u files. And there is no firmware 2.x for the 1541 U2 Plus.

Note: With firmware 3.x, you have to select an ".u2p"-File in the filebrowser to start the update. It will not start automatically.

For Ultimate 64:

*.u64 are used instead of *.u2p files. Otherwise the same as for 1541 Ultimate II+.

Note: With firmware 3.x, you have to select an ".u64"-File in the filebrowser to start the update. It will not start automatically.