PMCalls ->>
 PMSendMessage : < ULONG, ULONG, MPARAM, MPARAM > : < ULONG >
 PMPostMessage : < ULONG, ULONG, MPARAM, MPARAM > : < ULONG >

 ...

 MPARAM = Integer : 2^64 | Record
 ULONG = Integer : 2^32

 HANDLE = Integer : 2^32 : {?}    
 MSGQUEUE = HANDLE [MsgQueue]

 ...

;

## PM API : PMCalls -> {*}