<sect1>Joystick drivers<p>
-No joystick drivers are currently available for the PET.
+<descrip>
+
+ <tag><tt/pet-ptvjoy.joy/</tag>
+ Driver for the Protovision 4-player adapter contributed by Groepaz. See
+ <htmlurl url="http://www.protovision-online.de/hardw/hardwstart.htm"
+ name="http://www.protovision-online.de/hardw/hardwstart.htm"> for prices and
+ building instructions. Up to two joysticks are supported.
+
+</descrip><p>
<sect1>Mouse drivers<p>
<tt/ST/ variable.
+<sect1>Interrupts<p>
+
+The runtime for the PET uses routines marked as <tt/.CONDES/ type 2 for
+interrupt handlers. Such routines must be written as simple machine language
+subroutines and will be called automatically by the interrupt handler code
+when they are linked into a program. See the discussion of the <tt/.CONDES/
+feature in the <htmlurl url="ca65.html" name="assembler manual">.
+
+
<sect1>Using extended memory<p>
The extended memory at $9000 of the CBM 8x96 may be added to the heap by using