IBM 3270 Hardware User's Manual page 13

The system unit contains the processor and the
diskette or fixed disk drives. It has connections
to the other units and the host computers. The
processor runs the software that controls the
work station. The diskette and fixed disk drives
store information.
The display may be color or monochrome (one
color). It shows you what the processor is doing
and let's you see what you are doing.
You use the keyboard to tell the control program
what you want it to do and to type in the
information you want stored or processed.
You can" add an optional printer to the basic
work station. And there are some other options
that you can add to make your basic work
station do more or run faster. The 3270 PC is a
member of the IBM Personal Computer family.
And, like all the other members of the family, it
is designed to help you do your work. What
makes this Personal Computer different? It is
designed to bring together in one terminal an
IBM Personal Computer and access to one or
more IBM 370 host computers. U sing the IBM
3270 PC Control Program, you can work with
four host computers and more than one Personal
Computer application program at the same time.
The 3270 PC puts the convenience and flexibility
of the IBM Personal Computer and the enormous
processing and communications power of IBM
System/370 host computers under your fingertips.
1-2 Book 1 - 3270 PC Work Station User's Guide