Laser 128 - Page 83

INPUT/OUTPUT PORTS
However if you arc interested in writing
programs for the mouse yourself, you can
~ef er to the Technical Ref erence Ma1111a/ for a
detailed description of the operation of the
mouse.
6.1.6 Port 5 - Expa n sion memory
The computer comes with 1 28K system RAM.
This is more than su fficien t for most
applications. However, if it still cannot
satisfy your needs, you can easily expand the
RAM size up to 1 M-bytes!
IM - bytes= I 024 K-bytes
=1,048,576 bytes
This expansion memory is trca tcd as one of
the 1/ 0 devices of the computer which is
connected to port 5.
To install additional RAM in the computer,
please refer to APPENDIX B.
Un l ike the system RAM, the expansion RAM
is not directly addressab le and hence cannot
be used as program memory, i.e. a program
cannot run on it. Instead, it is primarily
designed for temporary data storage. A
typica l app l ication of the expansion RAM is
to use it as a "RAM disk", i.e. emulating a
very high - speed floppy disk system for
temporary storage of app l ication programs or
data files .
1-70