Simplest (practical) file system?

Joe wrote: <snip> Hold on here, the IDE drive (technically, the ATA drive, but nevermind that...) may have a buffer, this it quite irrelevant here. As soon as you hook your fast ATA disk up to a classic CPU like an HP1000 or an Imlac, you now have a slow disk system by any modern standard. Also, if the classic CPU is running the disk access code, there is another layer of performance hit. Another little detail of reality... Some HP disk systems force the use of DCPC (DMA) transfers. The boot mechanisim also forces the use of some linear files, files that use contiguous sectors on disk to store boot images. If some FAT system is used that allows non-linear files, then the code to control the DCPC logic has to deal with 2 cases, simple linear file transfers, and non-linear file transfers performed as a series of smaller DCPC block transfers. This is complexity I don't need, especially since many other disks don't demand DCPC transfers. Lets be a bit more analytical here, clearly people have deep seated emotions on the subject. This only complicates objective engineering. From all I've read so far, the only advantages FAT based approaches offer are: 1. Allowing efficient disk space use by implementing non-linear files. 2. Easing disk optimization tricks. But non-FAT based DOS's have been implemented, and once SQUEEZED, appear to be just as efficient as other schemes. Yes, fragmentation is an issue, but this is more easily solved (via SQUEEZE) then the code needed to maintain the FAT. Simplicity suggests that if its not needed, its not implemented. Traditional file systems tend to need to be tweaked in different ways (FAT sizes, cluster sizes, etc) for different kinds of media. I think there is a very different way to approach all this, and have a single scheme for all sizes of disks that will deliver a common level of efficiency in all cases. Think this is impossible? FORTH's block address scheme works. The trick is to very carefully adopt some features of other file systems while challenging their fundemental assumptions and take only what makes sense. I think there is a lot to be learned from vintage file systems like TSS-8, RT-11, Northstar DOS, etc. This discussion is fascinating and very helpful, but not being familiar with the guts of the variety of DOS's being thrown into the duscussion I'd really appreciate it if we could be a little more clear on the specific advantages each implementation choice implies. There seems to be a real lack of any objective anatomical dissection of different methods in print, at least in a readable (approachable) form. This is proably the only place such a discussion could ever take place, as so few people new to file system internals ever develop new approaches. What was the last 'really different' way to store stuff on disk?