Epson QX-10 - Manual (Page 26)

Light Pen Interface
Another convenient feature is an interface for a light pen, which
is a device used for tracing a diagram or object and producing the
image on the screen, or for choosing a menu option on the screen.
Option Cards
The QX-10 has space for five peripheral, or option cards. These
are special printed circuit boards that you can install in your QX-10
to add special devices and features. For example, you might want
to install a direct-connect modem card, a joystick, or a hard disk.
Chapter 3 explains the installation of option cards.
If this deluge of information seems a bit too much right now,
don’t worry. You’ll have time to explore the capabilities and features
of the QX-10 as you use it. The ease of operation and many useful
features of the QX-10 are what make owning and using this finest
of computers a real joy.
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