Microvax II hardware not recognized

Peter Coghlan cctalk at beyondthepale.ie
Fri Aug 19 03:56:36 CDT 2016

> >
> > Does Autogen recognize new hardware?
> >
> Yes, definitely.  Some older devices have switches (or even 
> soldered jumpers) to set the CSR address.  If some of these 
> are wrong, it could mess up the automatic address assignment 
> of later MSCP hardware.

Not exactly.

VMS automatically looks for and initialises I/O devices at startup
time. (There are exceptions to this but these do not come into
play in this particular situation.)

Autogen is another thing entirely.  It is a tool which you run
manually to set system parameters.  You don't have to run autogen
to pick up changes in your I/O setup.  You just have to have your
device configured the way VMS expects them to be and VMS will find
them when you boot.

In the case of later technology such as PCI, you can pretty much
plug a board into any slot and VMS will find it with no further
thought required.  In the case of Qbus / Unibus, there may be
settings on the board which have to be changed depending on what
other board are present and what order they are in before VMS can
correctly find them.  Wrong settings on or the absence or failure
of one board or the presence of an unexpected board can all prevent
VMS from finding other boards.

Peter Coghlan.

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