dg2l+@andrew.cmu.edu (Douglas Phillip Ghormley) (11/14/88)
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
steveb@cbmvax.UUCP (Steve Beats) (11/15/88)
In article <AXTWepy00V4=43CEQR@andrew.cmu.edu> 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