[Flossmaster]

My slot-loading CD-ROM drive swallowed a CD and wouldn't regurgitate it. It was on life support for a while, but eventually I had to "pull the plug," so-to-speak, and buy a new one. Life after death isn't so bad with a Firewire/USB 48x read-write drive. But now that my iMac has a hole in its head I'm inclined to fill it in with a second IDE hard-drive.

It seems to me that the second hard-drive would have to be slaved off the first drive. It all seems like standard hardware, the same components, cables, and power supplies used by IBM PCs. Anyway, if there's one thing I don't like, its grumpy relatives, and I'm concerned that adding another hard-drive to the family might make Mother Board complain, or worse yet, upset Papa OS. Does anyone else think there's a danger here? Thx.

[madmacs137]

I'm not sure, but I'm inclined to say that the iMac logicboard has two separate IDE buses. I think both my tray-loading cdrom and hard drive were set to "master" when I took my Rev A apart (the hard drive was jumpered and the optical drive has a switch on it).

If that's the case, the two hard-drives should be able to coexist peacefully.

Anyone else?

[sine -''-..-]

yes it should work fine.

i do believe there are two ide bus' on the imac mobo.

[bradoesch]

Hi!

When I opened my slot-loading iMac case, I noticed that there was only one cable going into my DVD drive. It wasn't a standard IDE cable, it carried power and the signal to the drive. Now, your CD-ROM drive might be different, I really don't know. I just know what my DVD drive is like.

Hope that helps you out,

Brad

[madmacs137]

The Rev A (tray-loading) cd-rom has a 50-pin IDE cable as opposed to the "normal" 40-pin cable. The extra pins provide the power and audio connection that are usually fed to/from an optical drive via other cables. The 50-pin connector actually has the same pin spacing as a 44-pin laptop HD IDE connector.

I would guess (but am not sure) that the pin-out of the data pins and maybe even the power pins is the same as on a laptop HD, meaning that the extra 6 pins on one end or the other are for the audio.

If your iMac has the same 50-pin IDE cable and you want to replace the optical drive with a HD, you could probably throw a 40-44 pin converter in (44-pin side connected to the motherboard), then a standard 40-pin IDE cable, then the HD. You'll probably want to provide the power to the 2nd HD by splitting the power cable for the 1st HD since most 40-44 pin converters only give you 5v and ground, not the normal 5v/12v/ground setup that most HDs use. I'm not sure how happy the OEM power supply will be about that though.

I haven't tried this myself, and your mileage may vary.

[madmacs137]

Of course, assuming the iMac has two IDE buses, you could just swap the stock single drive IDE cable for a two drive IDE cable and set one HD to master and one to slave. That way, you wouldn't have to deal with changing the 50-pin cd-rom connector to a 40-pin HD connector.

You'd still have an IDE channel to play with then.