On Thursday 23 February 2006 15:10, bobgoodwin wrote: >Mike McCarty wrote: >> bobgoodwin wrote: >>> Does it matter which forty pin connector plugs into the master and >>> slave drives? >>> I have come to the realization after struggling with some problems >>> that there are a lot more wires in the ribbon cable than there are >>> connector pins. >> >> If you have more wires than pins, you almost surely have a CABLE >> SELECT cable. In fact, if your cable is less than five years old, >> you probably have CS. Which end goes where depends on how you jumper >> your hard drives. >> >>> I now see that Maxtor designates the connector at the end of the >>> cable as the "master" and the one just below it as the "slave." I >>> presently have only one drive jumpered as master with FC4 running >>> on it and it >> >> If you use M/S jumpering on the drives, then in theory it doesn't >> matter where you connect them. > >Except it appears to me that it matters as far as terminating the line >properly is concerned. Ideally it would seem the termination should > be at the far end where the master is connected to avoid the > possibility of a mismatch at the end of the stub that would result if > the slave is at the far end. How much ringing might occur and the > severity of it's effect is an unknown? It would be interesting if I > could get into the circuit and poke around with a scope probe ... > >>> ;doesn't seem to care which data cable connector is attached to it, >>> but when I put in the second drive, jumpered as "slave" the >>> computer won't boot. I decided the drive was bad but now I'm >>> wondering? It may be the wrong connectors plugged into the drives. >>> >>> I thought "cable select" cables had wires obviously crossed in the >>> ribbon cable but that may not be true with this 80 wire ribbon? >> >> Not crossed. For CS, the drives have resistive pull-ups on them. The >> MB pulls down one line. The wire to this line is *severed* as the >> slave connector, so the "master" sees a high, while the "slave" sees >> a low on this pin. (The MB may have a pull-up and the drives a >> pull-down, I forget the polarity.) > >If the h/d manufacturer provided this explanation this thread would >never have started. I would have never asked any questions. It > appears that I probably have cable select which I will try here in a > little while. The drives can be jumpered for CS and I have 80 wire > ribbon cables so it appears that should work if I understand > everything I've read here? It would be helpful if the user knew that > he was dealing with a c/s cable, there is no mark apparently other > than the fact that there are more wires than connector pins to tie > them to? No, I believe the marker is the fact that each connector is a different color is what identifies a CS cable. As has been quoted here numerous times now, blue is the motherboard (or controller) end, grey IIRC is the end connector that should be plugged into the device that you want to be the master device, with the other, either black, yellow or red (IIRC I've seen all three of those colors used on 80 wire cables recently without really knowing what they meant) about 5-6 inches back from one end of the cable which is intended to be plugged into the slave device. And yes, all of the 6 or so drives I've picked up the last couple of days since this seemingly endless thread started, do require a jumper to be placed to put them into the CS mode. That isn't to say that they all do, but the ones I looked at, all required a jumper to put them in CS mode. The next 10 I pick up could make me wrong, but thats what I've observed in the last 2 days. >> Floppies have a "twist" in their cables, not hard drives. >> >>> Can someone clear this up for me. >> >> HTH >> >> Mike -- Cheers, Gene People having trouble with vz bouncing email to me should add the word 'online' between the 'verizon', and the dot which bypasses vz's stupid bounce rules. I do use spamassassin too. :-) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
