I have cleared some of my confusion with regards to cables using this site.
according to site, both 40 wires and 80 wire cables are IDE.
THe 40 wire cable is an ATA-33 cable whereas the 80 wire cable is an ATA-66/100 cable.
so if you attach an ATA 66, 100 or 133 drive using the 40 wire cable, you have introduced a bottleneck and the drive will run only at 33MB/sec.
I rummaged through my old stuff and discovered that you can actually see more wires on the 80 wre cable, the 40 wire cable has got the same width but the wires are thicker, at least they appear to be thicker externally. both the connector is the same, a 40 pin connector.
i think the new cables include a groove, which in addition to the red stripe running down the entire length of the cable helps us to connect the two devices.
All this reading has not cleared my confusion of IDE and EIDE devices. My BIOS says looks for IDE devices, not EIDE devices, and i read some place that most modern motherboards are equipped with EIDE adaptors. I also thought my latest WD 160 Gig drive would be an EIDE. According to the stuff i read, EIDE has been here since 1994.
my CD ROM is also using the same cable as my drive, so i am pretty confused.
what i understand from EIDE is that four devices could probably be stuck on one cable. so i guess the cable would be different, it should probably have three connectors.