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<title> OS/A65 Embedded Application Notes </title>
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<p><h1 align=center> OS/A65 Embedded Application Notes </h1></p>
<p><h2 align=center> (c) 1989-98 Andre Fachat </h2></p>
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<h3 align=center>OS/A65 Embedded Version 2.0</h3>
<h4>Introduction</h4>
<p>
Embedded applications normally don't have the amount of RAM and ROM
that a "normal" (whatever this means) system has. Therefore I have tried
to make some parts of the kernel removable, allowing for a much smaller
kernel to fit into embedded applications.
</p><p>
This way the more interesting features are still available, like
multithreading, signals and the device code. Some of the more sophisticated
kernel features can be removed however. For how to do this see
the <a href="kernel.html#config">config</a> section of the kernel
description. The application can be tested on a full-featured
system while the embedded kernel provides compatibility where necessary.
</p><p>
Parts of the kernel that can be removed are
</p><ul>
<li>streams
<li>memory management
<li>file manager
<li>send/receive
<li>semaphores
</ul>
<p>
This shortens the kernel to almost 2k in size.
Also the used amount of RAM is $bc = 188 byte normal RAM,
plus $e = 14 byte zeropage (not counting the environment, task and
thread-save 6 bytes from addresses 2-8), also not counting
the possible use of PCBUF by fork and devcmd.
1k RAM total should now be sufficient for simple applications.
</p><p>
Using the PCBUF without locking with a semaphore should be handled with
care, however.
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