Uniserver, I'm sorry you perceived my succinct reply as being rude. However I did misread your post. I did not follow the rationale behind your comments, and assumed you we're saying SuperDrives could not read and write 400k & 800k disks, hence the reason you transferred your images via zip to your SE (in which case your impression would have been wrong). Since I did not address your other points, aside from trying to explore the reasons why you may be encoutering problems on your 7500, they were never in question. Certainly I myself transfer images from my OS X Mac to my Plus via Zip all the time. My appologies. But thank you for confirming the statements I made in my post with your additional research. Hopefully this will lead to you being able to use your 7500 to format 400/800K disks in the future and eliminate the additional step of transferring to the SE. And thank you for sharing your Zip transfer method for those who also face this problem. While I am always looking to simplify the disk making process, often the least frustrating way is to keep the process in a native environment, even if it requires a little extra work.