Topic       : Pure Assembler Documentation
Author      : John Kormylo
Version     : PASM.HYP 1.0
Subject     : Documentation/Pure Assembler
Nodes       : 740
Index Size  : 20262
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : en
@default    : 
@help       : Help
@options    : +g -i -s +x +z -t4
@width      : 75
View Ref-File[ System Variables ]

... are mostly of interest when writing device drivers (which are
already in Supervisor Mode).   Many variables can be accessed through
BIOS or XBIOS functions.

System Variables by Address
System Variables by Name

Disk Drivers
Device Drivers
Screen Dump
Vblank
Cookie Jar

'vector' is an address for executable code.
'address' is an address for a data structure or jump vector table.
'magic' must contain a certain value (memory validity test).
'control' is used by the OS to control operation.
'data' is set but not used by the OS.
'reserved' either not implemented or should not be modified.