Apple Macintosh PowerBook 1400 Spécifications télécharger pdf (Page 53)

CHAPTER 4

Expansion Modules

Expansion Bay 39

Unused Signals 4

Several signals deﬁned in the standard interface for the IDE drive are not used by the

expansion bay. Those signals are listed in Table 4-7 along with any action required for the

device to operate in the expansion bay.

User Installation of an Expansion Bay Module 4

The user can insert a module into the expansion bay while the computer is in sleep

mode. This section describes the sequence of control events in the computer and gives

guidelines for designing an expansion bay module so that such insertion does not cause

damage to the module or the computer.

▲

WARNING

The user must not insert or remove a module from the expansion bay

while the computer is operating. It is safe to do so only while the

computer is in sleep mode or is off. Insertion or removal of a module

from the expansion bay while the computer is operating may cause

corruption of the internal hard disk. ▲

Sequence of Control Signals 4

Speciﬁc signals to the Baboon IC and the Power Manager IC allow the computer to

detect the insertion of a module into the expansion bay and take appropriate action. For

example, when a module with an IDE device is inserted, the computer performs the

following sequence of events:

1. When a module is inserted, the /DEV_IN signal goes low, causing the Baboon IC to

generate an interrupt.

2. The Power Manager IC reads the three DEV_ID signals, which identify the device as

an IDE device.

3. System software responds to the interrupt and sets a signal that turns on the power to

the expansion bay.

Table 4-7 Unused IDE signals

Signal name Comment

DMARQ No action required.

CSEL This signal must be tied to ground to conﬁgure the device as the master

in the default mode.

DMACK This signal must be pulled high (to the IDE device’s +5V).

IOCS16 No action required.

PDIAG No action required; the device is never operated in master-slave mode.

DAS No action required.

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Apple Macintosh PowerBook 1400 Spécifications Page 53