daemon@copper.ucs.indiana.edu (Mr Background) (01/01/91)
I own a removable hard disk which I like very much. There is only one
thing I feel a little annoyed and would like to know if this is the
same to all removable hard disk.
The thing is that I need to turn on the removable before I
turn on the Mac. If not, the Mac won't recognize the removable. Also,
once both the removable and the Mac are turned on, I cannot turn off
the removable and leave only the Mac on. If I do so, the Mac is freezed
until you turn on the removable again or you restart the Mac. The
reason I feel annoyed is that I would rather not leave the removable on
when I don't need the data in it and would like to turn it on any time
when I need it. But I cannot do this right now.
Another question I have is that if I take the cartridge out and
leave the drive on, will that save the life span of the drive? I found
that if I take the cartridge out of the drive, there seems nothing going
on in the drive except the power is on. I wonder leaving the drive on without
cartridges in it won't take any life span of the drive away. If that is the
case then it doesn't matter if I have to leave it on when I don't need the
removable. Anyone got comments?
Your input is appreciated!
-Peter Liuggw%wolves@cs.duke.edu (Gregory G. Woodbury) (01/01/91)
daemon@copper.ucs.indiana.edu (Mr Background) writes: > >I own a removable hard disk which I like very much. There is only one >thing I feel a little annoyed and would like to know if this is the >same to all removable hard disk. > > The thing is that I need to turn on the removable before I >turn on the Mac. If not, the Mac won't recognize the removable. Also, >once both the removable and the Mac are turned on, I cannot turn off >the removable and leave only the Mac on. If I do so, the Mac is freezed >until you turn on the removable again or you restart the Mac. The >reason I feel annoyed is that I would rather not leave the removable on >when I don't need the data in it and would like to turn it on any time >when I need it. But I cannot do this right now. > > Another question I have is that if I take the cartridge out and >leave the drive on, will that save the life span of the drive? I found >that if I take the cartridge out of the drive, there seems nothing going >on in the drive except the power is on. I wonder leaving the drive on without >cartridges in it won't take any life span of the drive away. If that is the >case then it doesn't matter if I have to leave it on when I don't need the >removable. Anyone got comments? Sure sounds like the semi-floppy removeable disks we use on our macs at the office. :-) The system freeze is a result of the way that the mac deals with the SCSI buss used to connect to the machine. However, we find that by making sure that the proper terminators are on the cables, this can sometimes be avoided. Non-recognition after start-up is a problem in the external file-system driver that the maker of the drive provides. You might want to check with their support bbs or RTFM to see if there is a program around to take care of this problem. For one brand, there was a program with older versions of the driver software that is no longer directly distributed, however, it still works with the latest version of the driver software and even with a similar model drive from a slightly different maker :-) We tend to leave the drive itself on, and remove the cartridges when not in use. Be sure that you properly unmount the cartridge so that you don't have to scramble for the disk at inopportune times. All the removeable cartridge drives that I have seen have a hardware feature that stops the motor and unloads the heads into a physically safe position when there is no cartridge in the drive. The life of the drive is a function of wear on the cartridge media and the cleaning of the heads. Properly cared for, leaving the power on without a cartridge in the drive should not change the life of the drive. Interesting question, tell me a bit more :-) -- Gregory G. Woodbury @ The Wolves Den UNIX, Durham NC UUCP: ...dukcds!wolves!ggw ...mcnc!wolves!ggw [use the maps!] Domain: ggw@cds.duke.edu ggw%wolves@mcnc.mcnc.org [The line eater is a boojum snark! ] <standard disclaimers apply>
mwang@.com (Michael Wang) (01/02/91)
In article <1990Dec31.181853.28607@bronze.ucs.indiana.edu> daemon@copper.ucs.indiana.edu (Mr Background) writes: > >I own a removable hard disk which I like very much. There is only one >thing I feel a little annoyed and would like to know if this is the >same to all removable hard disk. > > The thing is that I need to turn on the removable before I >turn on the Mac. If not, the Mac won't recognize the removable. Also, >once both the removable and the Mac are turned on, I cannot turn off >the removable and leave only the Mac on. If I do so, the Mac is freezed >until you turn on the removable again or you restart the Mac. The >reason I feel annoyed is that I would rather not leave the removable on >when I don't need the data in it and would like to turn it on any time >when I need it. But I cannot do this right now. [...stuff deleted...] I purchased a Syquest removable hard drive from Mirror Technologies a while back and had the same problem with the Mac not working unless the Syquest was turned on. I fixed the problem by taking out the internal terminator (a set of resistors) from the Syquest. Now the Mac boots up fine without the Syquest turned on. You should check with the company that built your drive to see if a similar procedure is recommended for your drive. Michael Wang mwang@oracle.com
rob@uokmax.ecn.uoknor.edu (Robert K Shull) (01/03/91)
In article <1990Dec31.181853.28607@bronze.ucs.indiana.edu> daemon@copper.ucs.indiana.edu (Mr Background) writes: > The thing is that I need to turn on the removable before I >turn on the Mac. If not, the Mac won't recognize the removable. Also, I would suggest the Mount'Em fkey for this. It will mount all unmounted SCSI partitions. Available on CIS, or send me mail and I'll mail you a copy. >once both the removable and the Mac are turned on, I cannot turn off >the removable and leave only the Mac on. If I do so, the Mac is freezed >until you turn on the removable again or you restart the Mac. The This depends on the drive. My Syquest is from Alliance Peripheral Systems, and doesn't show this problem. >-Peter Liu Robert Shull -- Robert K. Shull rob@uokmax.ecn.uoknor.edu chinet!uokmax!rob
steve@violet.berkeley.edu (Steve Goldfield) (01/03/91)
In article <1991Jan2.215035.17901@uokmax.ecn.uoknor.edu> rob@uokmax.ecn.uoknor.edu (Robert K Shull) writes: #>In article <1990Dec31.181853.28607@bronze.ucs.indiana.edu> daemon@copper.ucs.indiana.edu (Mr Background) writes: #>> The thing is that I need to turn on the removable before I #>>turn on the Mac. If not, the Mac won't recognize the removable. Also, #> #>I would suggest the Mount'Em fkey for this. It will mount all unmounted #>SCSI partitions. Available on CIS, or send me mail and I'll mail you a #>copy. #> #>>once both the removable and the Mac are turned on, I cannot turn off #>>the removable and leave only the Mac on. If I do so, the Mac is freezed #>>until you turn on the removable again or you restart the Mac. The #> #>This depends on the drive. My Syquest is from Alliance Peripheral Systems, #>and doesn't show this problem. #> #>>-Peter Liu #> #>Robert Shull #>-- #>Robert K. Shull #>rob@uokmax.ecn.uoknor.edu chinet!uokmax!rob The problem, as I understand it, is that the Mac does not like to have an SCSI device plugged in but not powered on. I don't think it depends on the type of device. My Mac won't boot in that situation either. However, you shouldn't have to put a removable cartridge in the drive to boot your Mac. You should only have to have the power switch for the drive turned on. Now whether or not your removable drive will then be visible at that point is probably a function of the software that comes with your drive. I know that DPI provides an init to look for and hook up its drive. In my case, I found that if I power up and load the cartridge first, my system will load from the removable instead of from my internal drive (because the removable is then up and running while the internal drive is still coming up to speed and because I have a system installed on my removable which I prefer not to remove). Steve Goldfield
rob@uokmax.ecn.uoknor.edu (Robert K Shull) (01/03/91)
In article <1991Jan2.232147.4576@agate.berkeley.edu> steve@violet.berkeley.edu (Steve Goldfield) writes: > >The problem, as I understand it, is that the Mac does >not like to have an SCSI device plugged in but not >powered on. I don't think it depends on the type of device. It depends on which model of Mac you have, and what kind of SCSI device. My understanding of the situation is this: Some Macintosh models supply terminator power through the SCSI port (at least Macintosh II and beyond). Some SCSI devices pass this terminator power through when they are powered off, and some don't. So, if you have a Mac that supplies terminator power, and a device that passes it through, you can leave that device off (or turn it off) while you use your Mac. If you don't, you'll end up with an unterminated bus and nothing will show. I have a Mac II with Rodime internal and APS Syquest external. Everything works fine with the external off or on. Now, I just added an Apple CD-ROM. Boom. Nothing works with the CD off, even if it's the only external device. Phttht. I think I'll open up the case and take a look at it, when the warranty expires. Robert -- Robert K. Shull rob@uokmax.ecn.uoknor.edu chinet!uokmax!rob
peter@hari.Viewlogic.COM (Peter Colby) (01/04/91)
In article <1991Jan2.232147.4576@agate.berkeley.edu>, steve@violet.berkeley.edu (Steve Goldfield) writes: |> In article <1991Jan2.215035.17901@uokmax.ecn.uoknor.edu> rob@uokmax.ecn.uoknor.edu (Robert K Shull) writes: |> #>In article <1990Dec31.181853.28607@bronze.ucs.indiana.edu> daemon@copper.ucs.indiana.edu (Mr Background) writes: ..... much ado about being unable to boot with a SCSI drive powered off. |> |> The problem, as I understand it, is that the Mac does |> not like to have an SCSI device plugged in but not |> powered on. I don't think it depends on the type of device. |> My Mac won't boot in that situation either. However, |> you shouldn't have to put a removable cartridge in |> the drive to boot your Mac. You should only have to |> have the power switch for the drive turned on. |> There are a number of possible causes for a problem like this. Once upon a time, when the Mac+ was still new, a version of the ROMs were buggy to the point where the Mac wouldn't boot if a powered off device was connected to the SCSI port. Another possibility has to do with the way your device is terminated. If your powered off device has it's terminator resistors connected to the bus but drawing their power from the device, this will also kill the SCSI bus. As a final note; I have an (ancient) Mac+ with an external HD. My SCSI terminators are on the HD itself (this is called internal termination) and I can Still Boot when my HD is powered off. In fact, this is the second HD I've owned with internal termination and I had similar lack of problems with the first. This is definitely a problem with your particular device, not with the mac. Peter C DISCLAIMER: Hey, what do I know anyway! -- (O)(O)(O)(O)(O)(O)(O)(O)(O) (O)(O)(O)(O)(O)(O)(O)(O)(O) (O) !the doctor is out! (O) (0) peter@viewlogic.com (0) (O)(O)(O)(O)(O)(O)(O)(O)(O) (O)(O)(O)(O)(O)(O)(O)(O)(O)
rich@sdchemf (Richard Kanner) (01/04/91)
In article <1991Jan2.232147.4576@agate.berkeley.edu> steve@violet.berkeley.edu (Steve Goldfield) writes: >The problem, as I understand it, is that the Mac does >not like to have an SCSI device plugged in but not >powered on. I don't think it depends on the type of device. > >Steve Goldfield That is not exactly true. I have currently hooked to my mac II one external jasmine 50 (off) and one APS syquest (on), and an internal quantum 105. I have never been able to to leave the SyQuest off and boot off my internal drive. I asked APS about this and they said that the SCSI terminator on the SyQuest needed to be powered up inorder to work. Consquently I power up the drive inorder to boot my mac from the internal drive if the SyQuest is hooked up. EOS R. Kanner UCSD Chem
stanfiel@testeng1.misemi (Chris Stanfield) (01/04/91)
In article <962@chem.ucsd.EDU> rich@sdchemf (Richard Kanner) writes: > I asked APS about this and they said that the SCSI terminator >on the SyQuest needed to be powered up inorder to work. This is true of all SCSI terminators. The SCSI spec. includes a signal called TERMPWR. This signal can be supplied by the host or the device. There are diodes used to prevent reverse power feed. Unfortunately, Apple, for some reason, omit this signal from their (non-standard) SCSI connector. I'm not sure why this is, because there is a spare pin on the connector (P25). Chris Stanfield, Mitel Corporation: E-mail to:- uunet!mitel!testeng1!stanfiel (613) 592 2122 Ext.4960 We do not inherit the world from our parents - we borrow it from our children.
russotto@eng.umd.edu (Matthew T. Russotto) (01/07/91)
In article <5901@testeng1.misemi> stanfiel@testeng1.UUCP () writes: >In article <962@chem.ucsd.EDU> rich@sdchemf (Richard Kanner) writes: >> I asked APS about this and they said that the SCSI terminator >>on the SyQuest needed to be powered up inorder to work. > >This is true of all SCSI terminators. The SCSI spec. includes a signal >called TERMPWR. This signal can be supplied by the host or the device. >There are diodes used to prevent reverse power feed. Unfortunately, >Apple, for some reason, omit this signal from their (non-standard) >SCSI connector. I'm not sure why this is, because there is a spare pin >on the connector (P25). Actually, pin 25 is used for TERMPWR on all Macs above the Plus, according to the hardware reference (this hardware reference also has pinouts for the ROM SIMM in the Mac II, so you might want to take it with a few grains of salt..) -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu .sig under construction, like the rest of this campus.