Autor: Smoq (smoq_at_poland.com)
Data: Fri 08 Jun 2001 - 22:50:49 MET DST
Użytkownik "Radoslaw Sokol" <rsokol_at_iname.com> napisał w wiadomości
news:3B1F2C70.BF613496_at_iname.com...
> Hi,
>
> Smoq wrote:
> >
> > Teoretycznie, bo zalecane jest, zeby master byl na koncu kabla.
>
> Nie, tak się nie zaleca :) Zaleca się jedynie, by jeśli na kablu
> jest tylko jeden dysk, to był on właśnie na końcu. Przy dwóch
> dyskach master może być na dowolnej wtyczce (jeśli kabel nie
> jest typu Cable Select, wymuszającego ustawienie Master/Slave).
>
W jednym masz racje, teoretycznie tak nie jest, ale praktyka pokazuje, ze
tak sie zdarza, zwlaszcza przy starszych dyskach. Wiec nalezy takie sytuacje
brac pod uwage.
A jak jest teoretycznie?
W specyfikacji ATA-5 i ATA-6 pisza tak:
This standard defines an interface containing a single host or host adapter
and one or two devices. One device is configured as Device 0 and the other
device as Device 1. The designation of a device as Device 0 or Device 1 may
be made in a number of ways including but not limited to:
a.. a switch or a jumper on the device;
b.. use of the Cable Select (CSEL) pin.
The host shall be placed at one end of the cable. It is recommended that for
a single device configuration the device be placed at the opposite end of
the cable from the host. If a single device configuration is implemented
with the device not at the end of the cable, a cable stub results that may
cause degradation of signals. Single device configurations with the device
not at the end of the cable shall not be used with Ultra DMA modes.
A w specyfikacji ATA-3 tak:
This standard defines the ATA interface containing a single host or host
adapter and one or two devices. If two devices are connected to the
interface, they are connected in a daisy chained configuration. One device
is configured as Device 0 and the other device as Device 1. The designation
of a device as Device 0 or Device 1 may be made in a number of ways:
a.. a switch or a jumper on the device
b.. use of the Cable Select (CSEL) pin
In a two drive configuration, a device shall be at one end of the ATA
interface cable and the host shall be placed at one end of the cable.
It should be recognized that if a single device is configured at the end of
the cable using CSEL, a device 1 only configuration will result. If a single
device configuration is implemented with the device in the middle, a cable
stub results that may cause degredation of signals.
Pozdrowienia
Smoq
To archiwum zostało wygenerowane przez hypermail 2.1.7 : Tue 18 May 2004 - 22:14:06 MET DST