CHAPTER 2
Hardware Modifications
8
200 MB Hard Disk Drive
Environmental Specifications 2 Table 2-2 provides a summary of environmental specifications for the 200 MB hard
disk drive.
Housing Requirements 2 The PowerBook Duo 250 computer accommodates either a 120 MB or a 200 MB hard disk
drive. The hard disk drive is housed in the PowerBook Duo 250 clamshell housing.
Mounting and installation requirements for the 120 MB drive are exactly the same as the
requirements described in Chapter 3 of the
Macintosh Developer Notes, Number 2,
Macintosh Duo System
.
The 200 MB drive is mounted in the same way as the 120 MB drive but has slightly
different dimensions. Figure 2-1 shows the dimensions of the 200 MB hard disk. The
height of the disk drive is critical, and it must not exceed 0.75 inches. The drive may be
mounted through either side-mounting or bottom-mounting holes machined into the
disk drive housing. A bracket, shown in Figure 2-2, is attached to the side of the hard disk
and holds it in place in the PowerBook Duo 250 computer housing.
Table 2-2
Environmental specifications for 200 MB hard disk drive
Category Condition Specification
Temperature of ambient
air inside a low airflow
thermal chamber,
non-condensing
Operating limits:
Nonoperating
and storage:
5 to 55 degrees C
-40 to 60 degrees C
Temperature gradient Operating:
Non-operating:
20 degrees C per hour
Below rate causing condensation
Relative humidity Operating:
Non-operating:
10–90%, noncondensing, maximum
wet bulb 20 degrees C
Noncondensing, maximum wet bulb
35 degrees C
Altitude Operating:
Shipping:
–200 to 15,000 feet
–200 to 15,000 feet