🚀 go-pugleaf

Meat Plow wrote:
> On Mon, 1 Mar 2010 15:08:05 -0600, VanguardLH <V@nguard.LH>wrote:
>
>> Rod Speed wrote:
>>
>>>> Signalling wise, there is no difference between a 40- and 80-wire
>>>> IDE cable.
>> <which is qualified in a following paragraph regarding cable select>
>>>
>>> Wrong. 80 wire cables are usually cable select cables, 40 wire
>>> cables usually are not.
>>
>> Get an ohmmeter to test.
>>
>> http://www.unitechelectronics.com/ide44pinout.gif
>> (this is the drive header, same pinout as for mobo header; remember
>> to mirror the image for ribbon connector)
>>
>> Cable select cables require a pin (#28) not be connected on one of
>> the device-side connectors.  I already mentioned in my prior post
>> how this can be done.  The host adapter grounds this signal (i.e.,
>> when connected, the device sees a ground line).  If pin 28 is
>> connected at the device (i.e., the device sees this signal is
>> grounded), it is the master device.  If this pin is open (floating),
>> that device is the slave.
>>
>> Just get a continuity tester to determine in pin 28 is open on one
>> of the device connectors on the ribbon cable.  I have 80-wire,
>> 40-pin cables that have pin 28 connected and some where it is open.
>> I have not seen a predominance of one or the other to claim a
>> "usual" configuration, and because of this is why I test.  It all
>> depends on who manufactured the cable.  For example, the
>> manufacturer might want that same 80-wire cable to be usable in
>> 40-wire cable setups so they feed pin 28 to all connectors. The same
>> holds true as to whether the connector or shroud are polarized with
>> a tang or notch, if depolarized by the absense of a tang or having
>> notches on both sides of the shroud, or if pin 20 is used as a
>> polarizing key (by pin 20 missing in header and blocked or solid in
>> the connector).  You have to look.  For cable-select or not enforced
>> in the manufacture of a 80-wire ribbon cable, you have to check with
>> a continuity check.
>>
>> If the connectors on the ribbon cable are color coded, I would
>> suspect cable-select was enforced through the physical connections
>> as follows:
>>
>>  - Blue:  Motherboard.    Pin 28 connected.
>>  - Black: Master device.  Pin 28 connected.
>>  - Gray:  Slave device.   Pin 28 not connected.
>>
>> But I'd still check pin 28 with a continuity tester to make sure.
>> You may not have cable-enforced cable-select with some 80-wire
>> ribbon cables (i.e., pine 28 goes to all connectors) when you want
>> to use cable-select on the device jumpers.  You may not want
>> cable-enforced cable-select if you are using jumpers on the devices
>> to configure them as master and slave.  Whether you have a
>> cable-select cable is something you should really test.
>
> Dell has been using Cable Select for at least 11 years.
> Long before 80 wire and UDMA 5 came to fruition.

And so did Compaq.