Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!hellgate.utah.edu!helios.ee.lbl.gov!ucsd!ucsdhub!hp-sdd!hplabs!hpda!hpcuhb!hp-ses!hpdml93!stephen From: stephen@hpdml93.HP.COM (Stephen Holmstead) Newsgroups: comp.sys.amiga.tech Subject: Re: Re: Tape Backup (was Hard Drive/Controller) Message-ID: <15450004@hpdml93.HP.COM> Date: 29 Nov 89 16:44:25 GMT References: <1989Nov21.224423.3829@athena.mit.edu> Organization: Hewlett Packard - Boise, ID Lines: 43 FelineGrace@cup.portal.com (Dana B Bourgeois) writes: >I know it probably isn't a problem now but when will support for more >than 8 SCSI devices appear? And do the current products support the >attach/detach elements that are built into the standard? SCSI has >been around for at least 5 years now and it seems there is only support >for a subset of the standard. What's the reason? Cost. As one who writes embedded SCSI controllers for a living, I can say that when we create a SCSI device, we go through the SCSI spec and say, "yes, people use this feature" and "nobody uses this feature, so we won't put it in". The more SCSI commands that we have to support, the higher the price tag that we are going to have to put on the device. In fact, we support TONS of the SCSI commands that are OPTIONAL according to the SCSI specification. We can't afford to spend money to support commands that controllers don't use. It doesn't make sense. BTW, SCSI-2 is on the scene. Lots of new features. Check it out! >And why don't we have SCSI modems? Don't tell me a 9600 BPS modem >wouldn't benefit from SCSI. Better yet, why wouldn't it be a good idea? Probably because of cost. But I forsee more devices becoming SCSI. I was looking through the SCSI spec and there are commands like "PLAY AUDIO", "READ CD-ROM CAPACITY", "START PRINT", etc. In fact, there are commands to support communications devices (modems), printers, scanners, processor devices, tape drives, and even automatic medium-changing devices! I guess if there was a demand, then people would start supporting it. But currently, to support SCSI on an IBM PC requires purchasing a $400 emulex controller. Thus, SCSI doesn't have much saturation on PCs, and thus, most hardware manufactures don't make modems, printers, etc, for SCSI. When the PC world starts to support SCSI, then you will probably see more SCSI peripherals. If you were a modem-maker, why would you make a modem that costs more than the ones on the market and can't be used by the bulk of the computers on the market? Sad, but true. :-( - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Stephen Holmstead ...!hplabs!hpdmlge!stephen // Hewlett Packard Disk Memory Division \X/ Amiga Forever! "I remind you that humans are only a tiny minority in this galaxy." -- Spock, "The Apple," stardate 3715.6.