What happenend to the original extended filesystem?
 

I have always wondered why I never have an option to format a partition with ext1 the lowest is ext2. Does Linux (kernel in this sense) even still support it?

according to http://en.wikipedia.org/wiki/Extended_file_system

seems like it was dropped due to issues with inodes and fragmentation.

If the extended filesystem is just an extention of the Minix filesystem does the MFS suffer from the same things?
If I had an old computer with a drive formatted with ext1 could I put it in my computer and accsess it from Ubuntu directly or has Linux dropped support for it?

I wouldn't say linux just dropped support for it since it is the distro vendors that choose not to include it. I am sure if you wanted you will be able to get the source and compile a kernel module, but I do not understand why you would go through such pain for an obsolete technology, current file systems will work just as well on old hard disks.

Regarding your MFS question, I would not be able to answer as I have no experience using minix as such. Not that I know or did research on the origin of extfs, if what you say is true, that it is forked, I would imagine the original MFS has the same or similar caveats, and they surely updated the filesystem specs on newer editions to address the shortcomings.

Sorry I cannot be more helpful, but interesting question you posed none the less.

Oh it's ok (the MINIX documentation is awful anyway).