Re: So how are the acheiveng the shielding?

Shielding is achieved by interleaving ground wires with the data wires, in other words, every second wire is ground (even though they are not necessarily grounded). If you split them and shrink them, you may end up with two data wires next to each other. The reason why the move to the 80 wire cables was done was exactly this issue, that is preventing cross talk between data lines and, thus, ensuring data integrity.

from a logical standpoint it makes sense but in reality, the advantages may be minor. Still, it is something to keep in mind if there are some abnoemal system glitches, cables are more important than most think. (been making too many myself)