Difference between IDE and SCSI ??

[Les Mikesell]

Nigel Henry wrote:
> 
> Sorry for the delay in asking this, but what is the difference between using 
> 40 pin 40 wire, and 40 pin 80 wire IDE cables?
> 
> I ask because on one of my machines I have a fixed harddrive, and also a 
> harddrive caddy that uses one of the 5 ¼ slots, and is where I plug my 
> various drives in, that have various multiboot installs on them. With a 
> standard 80 wire ribbon cable it's impossible to connect both drives, so I 
> used the end connector for the fixed data drive, and used an extension cable 
> from the middle connector to reach the harddrive caddy. The only extension 
> cables I could find were 40 wire ones. I started to notice that there were 
> some bootup problems showing up, when booting some distros, so changed the 
> cables over, so that the 80 wire end connection was now connected to the 
> harddrive caddy that dealt with the OS's, and the 40 wire extension was 
> connected to the fixed data drive.
> 
> This has resolved the bootup problems I was seeing.
> 
> As far as I understand this, an 80 wire cable with alternate wires grounded 
> physically separates the wires carrying data, and results in a better data 
> transfer to or from the harddrive. Please correct me if I'm wrong here.

That's correct - the extra wires are just grounds to prevent crosstalk 
at the speeds faster than the old 30Mhz speed that worked ok on 40 wires.

> I've tried to find 80 wire extension cables without success. Anyone living in 
> France know where I can find them?

No, but if you are looking to replace the setup, there are some nifty 
trayless SATA cages around that let you hot-swap bare drives.

-- 
   Les Mikesell
    lesmikesell at gmail.com