Path: utzoo!utgpu!water!watmath!clyde!att!ucbvax!hplabs!pyramid!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Request to Commodore (Fast File System)
Message-ID: <4604@cbmvax.UUCP>
Date: 30 Aug 88 20:53:22 GMT
References: <8808291950.AA12753@cory.Berkeley.EDU>
Organization: Commodore Technology, West Chester, PA
Lines: 27

in article <8808291950.AA12753@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) says:
> 
> :  I was thinking a while back about the Fast File System not being put on the
> :  floppies  in AmigaDos 1.3.  It is  my  understanding  ...
> 
> 	What I would like to see is an unmount command.... to unmount a 
> device (i.e. DF0:) then remount it under the new filesystem.  Even better,
> have the OS detect the disk format (easily done) and use the proper filesystem.

You mean like 1.3's "Assign UNMOUNT DF0:" 

> 							-Matt

You could probably set up a floppy with FFS, and it would be fast.  The other
problem you'd have is that it wouldn't know when a block went bad.  The standard
file system stores a 32 bit checksum in the block header of each block on your
disk.  Under FFS, there is no block header for data blocks.  This has the nice
feature of letting you store 512 bytes per block instead of 488, and it also
lets multiple blocks be transferred directly to their destination, without
any stripping.  This makes lots of sense using hard disks or similar devices 
that do hardware error checking that's far superior to the file system's 
checksum.  However, with a floppy, there is no underlying hardware error
checking logic; the checksum is all you get. 
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {ihnp4|uunet|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
		"I can't relax, 'cause I'm a Boinger!"