Newsgroups: comp.publish.cdrom.hardware Path: cdrom.com!barrnet.net!decwrl!decwrl!olivea!nntp.msstate.edu!gatech!swrinde!sdd.hp.com!saimiri.primate.wisc.edu!news.crd.ge.com!sarah!rpi!newsserver.pixel.kodak.com!mmdsw4!kruse From: kruse@sector.kodak.com (Mark Kruse) Subject: Re: Were's the problem? Drive or Driver? Message-ID: Sender: usenet@newsserver.pixel.kodak.com Reply-To: kruse@sector.kodak.com Organization: eastman kodak company References: <0097A708.EED013E0.11418@sgi.siemens.com> Date: Fri, 25 Feb 1994 16:03:20 GMT Lines: 36 In article 11418@sgi.siemens.com, lindstrom@sgi.siemens.com () writes: >Can someone tell me why one drive can support multi-session and another one >can't? Isn't it a limitation of the driver code and not a limitation of the >drive itself. I'm assuming that all drives allow random access to all >sectors/blocks on the disk. > >Tom >Lindstrom@sgi.siemens.com It is a combination. The drive must be able to understand the Orange Book Mode 5 pointers in the 1st TOC which point to subsequent sessions. The drive will only allow random access to the addresses that it KNOWS ABOUT. If it is a single session reader, it only knows about the track addresses in the first session and it is impossible (unless you have access to a secret command set) to tell it to go anywhere else. The driver must be able to handle that info plus whatever file system is layered on top and that file system must also understand multi-session if you are to be able to look at ALL of the data on the disc as one large file system. Or each session could stand as its own discrete file system. (Don't quote me on driver/file system stuff - I'm really best at the CD-ROM internal stuff). Mark Kruse Kodak 6X CD Writer Firmware --- ----------------------------------------------------------------------------- kruse@sector.kodak.com DISCLAIMER: I'm not a Kodak spokesperson. These are my opinions, not Kodak's.