Archived from groups: comp.sys.ibm.pc.hardware.storage (
More info?)
Folkert Rienstra <see_reply-to@myweb.nl> wrote
in message news:38t83eF5mjfhgU2@individual.net...
> Rod Speed <rod_speed@yahoo.com> wrote
>> Timothy Daniels <TDaniels@NoSpamDot.com> wrote
>>> Rod Speed wrote
>>>> Basically the standard requires every data line to have
>>>> a ground line between them with the 80 wire cables.
>>>> When its round, you dont have that.
>>> That is true. The "round" cables have a ground wire
>>> twisted together with each of the 40 data lines.
> And they all twist at the same 'speed' so there
> is always a ground wire next to a data wire.
Nothing like an 80 wire ribbon cable electrically.
>> Some do, some dont.
>>> Since the wire pairs inside a "round" cable can shift inside
>>> the outer sheath, it can't be known, and therefore can't be
>>> specified, what the degree of isolation between data lines is.
>> And the electrical characteristics of a twisted
>> pair are quite different to a parallel pair,
> Nonsense.
Fact.
> The SE impedance of twisted cables is in the 80-90 ohms,
> which is within the ATA impedance spec of 70-90 ohms.
There's more than just impedance involved.
>> and a twisted pair is usually driven differentially,
>> unlike the pair in the standard cable.
> So what.
Thats why the ATA standard doesnt allow that, cretin.
> SE inpedance is SE impedance and that is how they are used.
Even you should be able to manage a more viable troll than that pathetic effort.
>>> The isolation may be greater than with ribbon cables, or it may be less,
>> No reason why it should be greater.
>>> and it can vary from line to line, and it can vary between cables.
>>> That said, I haven't had any *descernible* problems with my
>>> "round" cables in the 20 months that I've used them.
>> Plenty claim that with other flouting of the standard too.
>> One obvious question is whether they would even notice
>> the electrical downsides of flouting the standard.
> What electrical downsides. There are none.
How odd that those who wrote the ATA standard dont see it like that.
>>> Since I have 3 hard drives, an optical drive, a Zip drive, and
>>> a floppy drive in the PC case, floppy cables make the use of
>>> all those devices possible while still maintaining good air flow.
>> The obsession with airflow is silly and if you dont have
>> adequate airflow with standard cables, the fix should be obvious.
>>> (Yes, there are "round" cables made for
>>> floppy drives as well as for IDE drives.)
>> Yep, plenty of complete abortions around.