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Xref: sserve comp.unix.bsd:1844 comp.unix.internals:4917 Path: sserve!manuel!munnari.oz.au!uunet!charon.amdahl.com!amdahl!veritas!amdcad!weitek!pyramid!ctnews!unix386!lance From: lance@unix386.Convergent.COM (Lance Norskog) Newsgroups: comp.unix.bsd,comp.unix.internals Subject: Re: Writing a device driver for CDROM Keywords: bsd devicedriver cdrom Message-ID: <8892@unix386.Convergent.COM> Date: 2 Jul 92 23:47:16 GMT References: <1992Jun20.152106.159@rai.juice.or.jp> Organization: Unisys/Convergent, San Jose, CA Lines: 23 Those of you working on CDROM support: please remember that some of will want to copy the CDROM onto a hard disk partition and use it from there. A few of us will want to produce our own CDROMs by building an image into hard disk. So, please don't make the CDROM file system require device-specific ioctl's to the SCSI driver. Now that I think of it, I'd like to allocate a disk partition as a "hot cache" of a CDROM; this would be a handy option to the CDROM file system. Those drives are really slow... Also, a group doing multimedia at Berkeley found that the cheapest way to get tight interactive real-time playback from CDROM is to have two drives and two disks. Buffering data on a hard disk works pooly because of causality issues. So, the CDROM software should be able to handle this transparently. Thanks a bunch, lance norskog thinman@netcom.com