The disc drive reads and writes data to and from the disc using a window space
which exposes the disc.
This window is covered by a metal shutter. The
shutter helps protect the disc surface from particles and accidental
The disc drive is equipped with a shutter opener. This means
that when the disc is placed in the drive, the shutter is automatically opened
exposing the disc surfaces.
The power light on the front panel flashes whenever its time to charge the
When there is a low battery indication, the battery provides a
reserve operating time of about five minutes, or a standby time of about
After the battery voltage drops below a minimum, the drive
will not respond to read or write operations.
This is to protect the stored
The adapter/recharger can be connected to the disc drive at any time. The
disc drive can be used while the battery pack is charging. In fact, it is
recommended that the adapter/recharger be used whenever possible, even when
the battery is fully charged.
A power-on self-test is performed automatically when the disc drive is turned
The fault light is the self-test indication. This light is on when
self-test is in operation.
The self-test takes approximately 6 (or 11)
seconds after which the fault light goes out. If the fault light stays on
after the normal testing time, an error within the disc drive has been
The read/write heads of the disc drive touch the disc. As a result, the
flexible disc media does wear.
Through a feature called Media Monitor, the
disc drive automatically monitors the cumulative use of each individual disc.
When the usage of a disc is approaching a level at which there is a risk of
loss of data through normal disc wear, the disc access light on the front
panel blinks and a clicking sound is heard.
THINKJET PRINTER (HP MODEL 22256)
The ThinkJet Printer (HP-2225B) is a battery powered, lightweight page printer
which can be easily transported anywhere.
This printer is small and has a
print rate of 150 characters per second (cps). The printer is powered by a
rechargeable 6.5V nickel cadmium (NiCad) battery. The printer also has a low
battery indication; printer stops operating at 6.2V.
A major feature of the ThinkJet printer is the quietness of its ink jet
The ink jet print head cartridge contains ink to print
approximately 500 pages.
The cartridge is completely disposable and easy to
Normal line length is 80 characters, with a paper width of 8.65 and
a paper length of 11.
The printer can use either single sheet paper (ink jet
recommended), or Z-fold pin feed paper.
The ThinkJet printer is capable of printing in two modes, text mode and
In text mode, the printer interprets each data byte it
receives from the computer as an ASCII character.
It then looks that
character up in its internal character table and prints the dot pattern which
directly specifies the
mode, however, the data received from the computer
dot pattern which is to be printed.