Mark.Bryant@p1.f54.n382.z1.FIDONET.ORG (Mark Bryant) (02/11/90)
DATE: 02/10/90 TIME: 11:33:21 Area: COMP.SYS.MAC Reply-To: Ed.Edell@f563.n107.z1.FIDONET.ORG In a message dated 02/10/90 at 11:33:21, Ed Edell writes: > Most of the time I can just unplug the > cable from the keyboard, and plug it back in, but sometimes I have to > reboot to make it all okay again. -Ed I've been told by an Apple service tech that this is a really hazardous thing to do. Sez he sees Macs all the time with blown ADB ports resulting from plugging and unplugging ADB devices while the machine is on. Probably best to power down before attempting to mess with ADB connections. -- Mark Bryant via cmhGate - Net 226 fido<=>uucp gateway Col, OH UUCP: ...!osu-cis!n8emr!cmhgate!382!54.1!Mark.Bryant INET: Mark.Bryant@p1.f54.n382.z1.FIDONET.ORG
Ed.Edell@p1.f563.n107.z1.FIDONET.ORG (Ed Edell) (02/12/90)
> I've been told by an Apple service tech that this is a really hazardous > thing to do. Sez he sees Macs all the time with blown ADB ports > resulting from plugging and unplugging ADB devices while the machine > is on. Probably best to power down before attempting to mess with > ADB connections. Well, I make sure things are lined up right ... -Ed -- Ed Edell via cmhGate - Net 226 fido<=>uucp gateway Col, OH UUCP: ...!osu-cis!n8emr!cmhgate!107!563.1!Ed.Edell INET: Ed.Edell@p1.f563.n107.z1.FIDONET.ORG
clarson@ux.acs.umn.edu (Chaz Larson) (02/14/90)
In article <41132.25D6F2C7@cmhgate.FIDONET.ORG> Mark.Bryant@p1.f54.n382.z1.FIDONET.ORG (Mark Bryant) writes: >In a message dated 02/10/90 at 11:33:21, Ed Edell writes: >> Most of the time I can just unplug the >> cable from the keyboard... > >I've been told by an Apple service tech that this is a really hazardous >thing to do. Sez he sees Macs all the time with blown ADB ports >resulting from plugging and unplugging ADB devices while the machine >is on. Probably best to power down before attempting to mess with >ADB connections. i can attest to this. I've seen three Macintosh IIs blow their motherboards because the user unplugged the mouse while the computer was powered up. Always power down the machine before adding or removing ADB devices. <chaz>
mjkobb@mit-amt.MEDIA.MIT.EDU (Michael J Kobb) (02/14/90)
In article <1142@ux.acs.umn.edu> clarson@ux.acs.umn.edu (Chaz Larson) writes: >i can attest to this. I've seen three Macintosh IIs blow their motherboards >because the user unplugged the mouse while the computer was powered up. >Always power down the machine before adding or removing ADB devices. Nice job, Apple. I find it kind of inexcusable that they don't have a warning in huge letters somewhere obvious in the documentation for ADB machines. I knew that the ADB was dangerous, so I've never done that to my IIx, but it was nowhere that I read in the docs. I wonder if they plan to make this a bit more robust? Considering the design of the machine, it's really easy to accidentally unplug an ADB device (especialy with third-party keyboards like my Mac-101 with the ADB on the back edge). Pull the keyboard too far away from the machine, and PING! Bye, bye motherboard. --Mike
nebel@wam.umd.edu (Chris D. Nebel) (02/15/90)
In article <1142@ux.acs.umn.edu> clarson@ux.acs.umn.edu (Chaz Larson) writes: >i can attest to this. I've seen three Macintosh IIs blow their motherboards >because the user unplugged the mouse while the computer was powered up. >Always power down the machine before adding or removing ADB devices. I find this whole thing a bit strange. Before I heard about other people having problems with this, I would plug and unplug ADB devices while the machine was on all the time. Never had the slightest problem. I've gotten paranoid in my old age :) so I don't do this any more, but it seems very odd that I could do this something like 50 times without ever zorching my machine. Maybe I'm just lucky... Chris Nebel nebel@wam.umd.edu
tbutler@wpi.wpi.edu (Tim Butler) (02/15/90)
In article <41146.25D6F6AC@cmhgate.FIDONET.ORG> Ed.Edell@p1.f563.n107.z1.FIDONET.ORG (Ed Edell) writes: > > I've been told by an Apple service tech that this is a really hazardous > > thing to do. Sez he sees Macs all the time with blown ADB ports > > resulting from plugging and unplugging ADB devices while the machine > > is on. Probably best to power down before attempting to mess with > > ADB connections. > > Well, I make sure things are lined up right ... -Ed I don't think lining things up is the problem. The connecting is to a bus that has addresses. If you plug something in while it is on, it is supposedly going to have addressing problems. It would seem that just sticking it back in after it fell out wouldn't cause a problem, but rebooting doesn't take that long. -Tim (I am by no means a hardware expert, I am just remembering what I've read) Tim Butler (tbutler@wpi.wpi.edu) Teaching Assistant HL 103b ext.5424 Department of Mechanical Engineering Worcester Polytechnic Institute
allbery@NCoast.ORG (Brandon S. Allbery) (02/16/90)
As quoted from <1615@mit-amt.MEDIA.MIT.EDU> by mjkobb@mit-amt.MEDIA.MIT.EDU (Michael J Kobb): +--------------- | In article <1142@ux.acs.umn.edu> clarson@ux.acs.umn.edu (Chaz Larson) writes: | >i can attest to this. I've seen three Macintosh IIs blow their motherboards | >because the user unplugged the mouse while the computer was powered up. | >Always power down the machine before adding or removing ADB devices. | | Nice job, Apple. I find it kind of inexcusable that they don't have a warning | in huge letters somewhere obvious in the documentation for ADB machines. I +--------------- Not in huge letters, but it's on page 10 of the SE owner's manual in the "Keyboard and mouse" section. Perhaps Apple's failing was making a machine so easy to use that even fewer people than usual bother to actually *read* the manual! ++Brandon -- Brandon S. Allbery allbery@NCoast.ORG, BALLBERY (MCI Mail), ALLBERY (Delphi) uunet!cwjcc.cwru.edu!ncoast!allbery ncoast!allbery@cwjcc.cwru.edu
minich@a.cs.okstate.edu (MINICH ROBERT JOHN) (02/16/90)
[multiple levels of previous stuff you need not read again about unplugging ADB devices while machine is on] Tim Butler writes... > I don't think lining things up is the problem. The connecting is to a bus > that has addresses. If you plug something in while it is on, it is > supposedly going to have addressing problems. It would seem that just > sticking it back in after it fell out wouldn't cause a problem, but > rebooting doesn't take that long. > > -Tim > > (I am by no means a hardware expert, I am just remembering what I've read) > Tim Butler (tbutler@wpi.wpi.edu) > Worcester Polytechnic Institute When an ADB device (keyboard/mouse/?) is unplugged, the Mac will soon find it missing. It polls all the ADB devices many times every second. When you put a new device on the bus, it should have the effect of resetting the entire bus. (Although I'm not sure wether the Mac or the device is responisble for that part.) Anyways, the real problem with lots of unplug/replug cycles is the chance of static buildup zapping a chip. (Worse case, the chip on the motherboard, which is a board swap at the dealer. :-( ) Someone mentioned this before, but I think it bears repetition: The original keyboard cabling scheme was VERY good. Ma Bell isn't too stupid. Phone style connectors are really great things, an example of practical engineering. Maybe Apple could change the connectors for ADB to phone style ones. And for that matter, also LocalTalk cables. The choice of cabling for the Mac (SE and up) is ironic: the cables on the back that are almost never jostled the slightest bit are screwed on tightly while the cables that get tugged, yanked, and otherwise abused on a regular basis just pop out. Does anyone at Apple (or anywhere else) now FOR SURE why the current connectors were chosen? Just curious. Robert Minich minich@a.cs.okstate.edu Oklahoma State University "Where the faculty in favor of canning our give-a-football-player-a-diploma-'cause-he- works-real-hard-even-tho-he's-not-making- minimum-standards President" I disclaim nothing because if the officialdom can get away with BS, this should hardly even be noticied.