Apple UniDisk 3.5: Specifications (Discontinued)

I. Technical Specifications

A. Recording Media:

1. Disk diameter: 3.5 inches

2. Recording surfaces: 2

WARNING: Disks used in UniDisk 3.5 must contain certified
DOUBLE-SIDED media.

3. Tracks per surface: 80

B. Capacities:

1. Formatted data: 800 kilobytes

2. Unformatted data: 1,246 kilobytes

C. Driver Characteristics:

1. Access Time:
a. Seek time (track to track): 6 milliseconds maximum
b. Settle time: 30 milliseconds maximum
c. Drive-motor start time: 600 milliseconds maximum

2. Transfer Rate: 500 Kilobits

3. Eject time: 2 seconds maximum

D. Power Consumption:

1. +12 volts
a. Standby: 10 microamps
b. Typical: 120 milliamps
c. Peak: 600 milliamps during eject

2. +5 volts
a. Standby: 170 milliamps
b. Typical: 360 milliamps

E. Head Position Tolerance: Plus or minus 0.035 mm

F. Environmental Requirements:

1. Temperature:

Degrees
Fahrenheit Celsius
a. Operating: 40 to 120 5 to 50
b. Nonoperating: 40 to 140 -40 to 60

2. Humidity: 5% to 90%
a. Maximum wet bulb temperature: 85 F, 29 C
b. No condensation

G. Physical Dimensions:
inches millimeters
1. Length: 7.87 200
2. Width: 4.72 120
3. Height: 2.01 51

II. System Configuration:

A. Apple IIc

-- A second UniDisk 3.5 can be plugged into the first

-- An additional Disk IIc can be plugged into the first (or second)
UniDisk 3.5

B. Apple II, Apple II Plus, Apple IIe

-- With UniDisk 3.5 Apple IIe Accessory Kit

-- A second UniDisk 3.5 can be plugged into the first.