Yes, sure.
Working with MyIDE-partitions is for advanced users, so you have to understand the why / why not yourself.
MyIDE-partitions are different then PC-partitions, nor can you read both or interact between them on the Atari.
The MyIDE-manager helps you on the PC to transfer disks (ATR) to from your CF-card.
1/
You need to update the cartridge content first.
http://www.mr-atari.com/Mr.Atari/MyIDE-ONLY/Version #7 is the latest.
[Download and read the manuals found here]
http://www.mr-atari.com/Mr.Atari/MyBIOS/2/
Then you need on your PC the MyIDE-manager.
viewtopic.php?f=17&t=15923/
Now, pop the CF card in your PC-reader start the manager.
Copy the ultima disks in sequence on the image-partition.
If the CF has no MyIDE-partition, it will complain I guess.
>Then you have to run the MyIDE-menu on the atari
>!!! This will delete all data present, so make a backup of your files first !!!
>Select 2 (MyIDE-only), select 1 (myide-menu setup)
>Just do auto init, exit/save
>goto 3
4/ Once the disks are on the CF.
Boot the atari, select 2, select 2, select the first diskette (arrows/enter or joystick/fire)
You are back in the bootscreen, image-mode selected and ready to go.
Most likely the disk boot does not need BASIC, so press enter.
This boots disks 1.
5/ when ever you need to switch disks.
press/hold shift+control+number and wait for the beep.
Remember that in image-mode, disks are write protected, so if you want to save to a mounted disk:
You need to press/hold shift+control+P (toggle protection) and wait for the beep.
Then save your game status.
Try dallas-quest first, to get going and getting used to MyIDE-partitions.
This one works 100% sure.
Ultima, I don't know.
MyIDE-ONLY is most likely compatible, if not, you can try MyBIOS-RAM-FMP