Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!know!tegra!vail From: vail@tegra.COM (Johnathan Vail) Newsgroups: comp.periphs.scsi Subject: Re: Why scsi printers? Info wanted. Message-ID: <2068@atlas.tegra.COM> Date: 15 Feb 91 17:02:26 GMT References: Distribution: comp.periphs.scsi,comp.periphs.printers Organization: Tegra-Varityper, Inc., Billerica, MA Lines: 42 In-reply-to: andyc@bucky.intel.com's message of 14 Feb 91 08:44:14 GMT In article andyc@bucky.intel.com (Andy Crump) writes: I have heard talk about postscript printers with SCSI interface. One use of the scsi interface is so that the printer can have a local disk to store fonts. But I have heard talk that the scsi interface can be used as a communication mechanism. I am not clear on what the advantage is to a SCSI printer. It seems to me that the speed of the print mechanism is by far the limiting factor to print speed, not the I/O port. Unless the SCSI postscript printer has ALOT of local memory to queue up jobs... Speed of the transfer. SCSI is many orders of magnitude greater than most other interfaces available. Most printers can't keep up at 9600 baud anyway. Why would anyone want to use SCSI as their I/O channel to a printer? What printers implement this and how are they used? How pervasive are SCSI printers, where SCSI is used as the communication channel? Inquiring minds want to know. On your average *printer* this is true. When you get into imagesetting and postscript you start talking about *lots* of data. There the rendering and transfer times can far outweigh the time spent by the output devices. Some color seperations for postscript are easily 40 to 50 *megabytes*. And this is for a single page. In this perspective it is easy to see how transfer times become crucial and why SCSI is one way to attack this. As for use as of today I haven't seen too many of them. This is changing, though. jv "Honesty without Fear" -- Kelvinator _____ | | Johnathan Vail | n1dxg@tegra.com |Tegra| (508) 663-7435 | N1DXG@448.625-(WorldNet) ----- jv@n1dxg.ampr.org {...sun!sunne ..uunet}!tegra!vail