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Interrupt problems

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git-svn-id: svn://svn.cc65.org/cc65/trunk@2812 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2003-12-21 18:47:29 +00:00
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doc/cbm610.sgml
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@ -229,6 +229,16 @@ While this simplifies things, it should be noted that the wrappers do have
quite an impact on performance: A cross bank call has an extra 300µs
penalty added by the wrapper.
<sect1>Interrupts<p>
Compiled programs contain an interrupt handler that runs in the program bank.
This has several advantages, one of them being performance (see cross bank
call overhead mentioned above). However, this introduces one problem:
Interrupts are lost while the CPU executes code in the kernal bank. As a
result, the clock may go wrong and (worse) serial interrupts may get lost.
Since the cc65 runtime does only call the kernal for disk I/O, this means that
a program should not do file I/O while it depends on interrupts.
<sect>Other hints<p>