Commodore Amiga A500 Technical Reference Manual page 136

ACCESS, MEM_GRAPHICACCESS, or MEM_IOACCESS. See the
hardware description for the meaning of these access methods if
you do not already know.
FreeJanusMem( ptr, size )
A1 DO
The specified memory is returned to the free pool. Some modest er-
ror checking is done, and the system will Alert if there is a problem.
ptr = JanusMemBase( type )
DO
The base of the memory referred to by the type specifier is
returned. See AllocJanusMem for a (very) brief description of type.
type = JanusMemType( ptr )
DO
The type of the pointer is returned. "Unpredictable results" will oc-
cur if ptr points to neither buffer memory nor parameter memory.
offset = JanusMemToOffset( ptr)
DO
If ptr points to buffer or parameter memory, the offset from the
start of that memory to ptr will be returned. This is the value that
should be fed to SetParamOffset( ) if this is a parameter block.
offset = GetParamOffset( jintnum )
DO
The parameter offset for interrupt jintnum is returned. The system
does not interpret this number, but by convention a $ffff means
that no parameter block has been set up.
oldOffset - SetParamOffset( jintnum, offset )
DO D1
The parameter offset for jintnum is set to the bottom sixteen bits of
offset The previous offset is returned. The system does not inter-
pret this number. but by convention a $ffff means that no
parameter block had previously been set up.
ptr = GetJanusStart()
The base of the janus board is returned.
setupSig = SetupJanusSig
(jintnum, signum, paramsize, paramtype)
DO Dl D2 D3
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