Path: cdrom.com!barrnet.net!agate!howland.reston.ans.net!pipex!sunic!seunet!seunet!holytoy!news From: martin@brax.se (Martin Nilsson) Newsgroups: alt.cd-rom Subject: Re: SCSI I VS SCSI II Message-ID: Date: Mon, 30 May 1994 08:56:11 +0100 (CET) References: Organization: Braxen BBS, Loeddekoepinge, Sweden -> INT+46-46-712396 Lines: 33 X-Newsreader: ZipNews Reader/Mailer v0.92xa (Beta) In article Shane.Gray%1039%okgate@yokm.pillar.com writes: > What are the advantages of a SCSI II over the older SCSI I interface? I have herad that a SCSI-1 device ties up the bus during the whole request so that no other request can take place while the CDROM finds the requested block. A SCSI-2 device on the other hand takes a request and frees the bus until it has data to transfer thus allowing a fast device like a HD to use the bus the time it takes the CD to find the block. Is this correct? Can anybody confirm this? This won't help a DOS computer a bit since DOS can only perform one IO request at a time, but advanced OS:es like OS/2 and UNIX would benefit a lot. It would also be much better in a file server. > I am thinking about the Pro Audio Spectrum or > Soundblaster cards with the SCSI interface on the board. Will I be > able to connect a tape drive backup to the card later? A cheap SCSI controller should not slow down a tape or slow CDROM drive. Tape speed is approx 12MB/min -> 200KB/s and a CDROM is 150-450KB/s sustained. I'm a bit concerned about a 8-bit controller being able to handle 450KB/s sustained throughput though. /Martin ----- Martin Nilsson, Computer Science and Technology student at martin@brax.se Lund Institute of Technology, Sweden SysOp on Braxen BBS, UseNet & FidoNet capable BBS Node 2:200/0 +46-46-712396 The 486 must be the slowest CPU you can buy for such a large amount of money!