View Full Version : Holy Jumpers Batman

04-25-2001, 10:35 AM
Now that I've installed my beautiful new IBM 75GPX 75gig hard drives, I am not sure about the jumper configurations (those little white thingies on the back of each drive). I've checked out IBM's web page, but it doesn't make sense to me - Master, Slave, Cable Select, Forcing Device 1 present - sounds like a scene from an S & M movie. Can someone help here. I plan on running OS 9.1 on one drive, and OS X on the other. Thanks.


04-25-2001, 11:06 AM
Your computer needs some way to distinguish one hard drive from another, quickly and efficiently. That's the purpose that the jumpers serve. On an IDE bus, you can have two drives on the same bus (cable) and typically one is designated Master and the other is designated Slave. If you are going to put both drives on the same cable, you would just want to make sure that one of your drives is set to Master and the other is set to Slave.

If a drive is alone on a bus, then you usually set it to Master. However, some drive manufacturers have a Single setting which is different from the Master setting, so it is important to read the documentation. You can get odd behaviour if you set a lone drive to Master when it could have been set to Single.

Cable Select will never matter to you, but it is used with a special IDE cable. The cable has some wires rearranged, so that the position of the drive on the cable identifies the drive as master or slave. If you were using one of those cables, then you would set the drive to Cable Select.

I'm not sure about Forcing Device 1 present, but I'm pretty certain you don't need to concern yourself with that either.

05-13-2001, 02:33 AM
Some hard drive vendors might say "Master" (solo drive) or "Master with Slave Present" to tell the drive or IDE bus that there will be a slave drive attached.

05-13-2001, 07:51 PM
I've got my primary drive "Abbott" set up as the master, and the secondary drive "Costello" as slave. Both appear nicely on the desktop. I use Costello mostly for backup, but also to boot from as a utility disk (I copied DiskWarrior onto it). Everything is cool until I try to install OS X onto Costello. I am informed by the installer that everything installed normally, but when the thing reboots, I'm told that the Home file is missing. Everything in the dock is a generic folder icon, and I can't do a damn thing with the software - it just hangs. Could this problem be due to the way I have the drives configured, or is it a software thing?

05-13-2001, 09:42 PM
I don't see what machine this is. There are several possibilities here. If it's a beige G3, OS X requires special care and feeding when installing.

If it's a beige G3 or early B&W, you can't just throw an Ultra DMA/100 in there and go without the danger of HD corruption due to timing. Because of the light- weight Apple ATA controller in those machines, you must set the single page, multipage, and DMA modes properly to avoid corruption.

[This message has been edited by Louie (edited 13 May 2001).]

05-13-2001, 11:29 PM
Thanks for the feedback. I'm using a DP 450 G4 with 512 megs of RAM. Should that have anything to do with what's happening?

05-14-2001, 03:56 PM
I don't think so.

05-15-2001, 08:29 AM
I would install OS9.1 and OSX on one drive....and then use the other drive for a working version of OS9.1.

on the first drive, the version of 9.1 you install will be used for the Classic environment.

i have yet to see a machine actually work with ONLY OSX on one drive, and OS9.1 on another. For some reason, every OSX drive I have built wants OS9.1 on the same drive. You don't necessarily have to use it....and you probably shouldn't, if you want to keep things safe and clean....but you will have to pay attention in the Startup Drive control panel and X system preferences. It can get gnarly in there. I've had to actually zap PRAM to make machines boot off the correct partition, all kinds of weird stuff.

05-15-2001, 12:30 PM
Thanks for the tip. However, when I tried this, the same thing happened. I use my Master drive as sole 9.1. I placed 9.1 on my slave drive, then installed OS X onto the slave; but X still comes up with the 'Home' file missing and does nothing. Could it be because it's on the slave and not the master?

05-15-2001, 05:07 PM
I think OS X wants to be on the Master.