HP OpenVMS Systems

Connect-To-Interrupt (CONINTERR) on Alpha?

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The Question is:

 
There is a connect-to-interrupt facility on VAX/VMS
supported by CONINTERR driver.
 
There is no CONINTERR driver on Alpha VMS 6.2 and higher,
but there are still QIO function codes IO$_CONINTREAD
and IO$_CONINTWRITE in IODEF sections. Search over .*.tlb
also shows some traces of connect-to-interrupt facility.
 
Was connect-to-interrupt facility completely removed from
Alpha, or it is supported by another system component?
What are the changes,  where can I read about it?
 

The Answer is :

 
  There is no connect-to-interrupt (CONINTERR) on OpenVMS Alpha, and never
  has been.  This is an OpenVMS VAX feature, and one that was not ported.
 
  IIRC, the CONINTERR-related IO function codes IO$_CONINTREAD and
  IO$_CONINTWRITE were only documented for use with the Laboratory
  Peripheral Accellerator package(s).
 
  The OpenVMS Alpha replacement for the CONINTERR driver is a standard
  device driver, potentially written in C.   See the device driver book.
 
  Some of the underlying changes that can be required in the application's
  memory management access model -- swizzling, dense and sparce address
  space are some of the requirements for memory references on Alpha systems
  platforms targeting EV5 and prior processors -- would make porting existing
  CONINTERR-based code "interesting", even with a CONINTERR driver available.
 
  As for finding the symbols, we regularly share common sets of definition
  files between OpenVMS VAX and OpenVMS Alpha, this to avoid skewing symbol
  definitions that could easily result from a platform-unique definition file.
 
 

  

     

     
answer written or last revised on ( 6-NOV-2001 )
     
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