Path: utzoo!attcan!uunet!cbmvax!steveb From: steveb@cbmvax.UUCP (Steve Beats) Newsgroups: comp.sys.amiga.tech Subject: Re: FFS sectors Message-ID: <5228@cbmvax.UUCP> Date: 14 Nov 88 16:10:02 GMT References: Reply-To: steveb@cbmvax.UUCP (Steve Beats) Organization: Commodore Technology, West Chester, PA Lines: 28 In article dg2l+@andrew.cmu.edu (Douglas Phillip Ghormley) writes: >Does anybody out there know what the format of each sector is in the FFS? The >AmigaDos Manual goes into nice detail for the old file system, but the manual >that comes with 1.3 doesn't (that I could find). I know that data sectors >contain only data, but what about drawers? Where does the system keep track of >the order of the sectors in the file? How does the system keep track of which >sectors have and have not been used? etc, etc... > >-Douglas Ghormley > dg2l+@andrew.cmu.edu There are three main differences between an FFS partition and an oldfs one:- 1) Data blocks contain nothing but data 2) Hash chains are sorted from lowest to highest block numbers 3) The boot block contains 'DOS/1' instead of 'DOS/0' all of the file headers and extension blocks are in exactly the same format as the old filing system (with the exception of bitmap pointers). I made a conscious decision to implement it this way so that disk utilities could be ported to FFS with the minimum of pain. I have written an article/document listing the differences (and re-hashing the old information) for AmigaMail, but I'll have to wait until it's published before I can make a more general release. Steve