Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!psuvax1!rutgers!cbmvax!jesup From: jesup@cbmvax.commodore.com (Randell Jesup) Newsgroups: comp.sys.amiga.programmer Subject: Re: Mike Farren Tutorial. Message-ID: <20195@cbmvax.commodore.com> Date: 29 Mar 91 03:00:55 GMT References: <1991Mar24.204206.11145@starnet.uucp> <1991Mar26.211403.8981@engin.umich.edu> Reply-To: jesup@cbmvax.commodore.com (Randell Jesup) Organization: Commodore, West Chester, PA Lines: 23 In article mykes@sega0.SF-Bay.ORG (Mike Schwartz) writes: >If you have 4 drives, >trackdisk.device eats up 40K. The trackdisk.device routines do not >use the DSKSYNC capabilities of the drive. Custom loaders can improve >performance by avoiding extra disk revolutions (this is done by timing >when you write to the disk in the first place). Actually, trackdisk uses more like 20K/drive (though that includes the filesystem, which isn't an issue for a bootblock game). The 2.0 trackdisk does use WORDSYNC/DSKSYNC. It helps, but it's an incremental improvement, not an order of magnitude one. Trackdisk doesn't wait for disk revolutions, it starts dmaing immediately (under 1.3) or when a sync is seen (under 2.0). Only if you need to use part of the data before you've had time to load it all in would aligning the track skews make sense. -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com BIX: rjesup Thus spake the Master Ninjei: "To program a million-line operating system is easy, to change a man's temperament is more difficult." (From "The Zen of Programming") ;-)