On Date: Wed, 25 May 2011 22:15:53 -0400, Michael Kerpan <[email protected]> 
posited:

> Given that IIRC, VMS does its hardware detection during install, how
> did you go about getting the system to see the hardware present in the
> VaxStation and forget about the stuff in the Vaxserver 3900?

VMS implements the system and device configuration at bootstrap.  The platform 
console finds and loads the primary bootstrap VMB, APB or IPB image into memory 
(from the system disk or from external console storage (and remember 
CONSCOPY.COM or EXCHANGE to update the console media), depending on the VAX), 
and the primary bootstrap then uses the console and its own pieces including 
the primitive file system to find and to get SYSBOOT into memory, and SYSBOOT 
loads enough additional parts to kick off the rest of the bootstrap.

The original MicroVMS stuff might have caused some confusion around the 
implementation details here, as that was a subset distribution specifically for 
storage-constrained MicroVAX processors. In various cases including the Local 
Area VAXcluster (LAVc) support, the system manager ended up loading full VMS 
onto the box.  And the MicroVMS distribution was discontinued when the MicroVAX 
storage became sufficient for a (potentially tailored) VMS installation.  

This generic nature of the VMS bootstrap also plays into the DEFAULTS settings 
for the system parameters, too.  The SYSBOOT (and SYSGEN) defaults are just 
good enough to get most any VAX box to boot far enough to run AUTOGEN and fix 
the parameters.  (While there have been a few parameter "bugs" here over the 
years that could cause problems booting some boxes, these settings and this 
behavior holds for most VMS and OpenVMS releases.)

The advent of CDs and TK50 as bootable VMS installation media was a substantial 
improvement over what was available prior to that, too; installing all of 
MicroVMS and ancillary pieces could involve thirty and often more floppies.

The older VAX-11 processors differed substantially from one model to the next 
and which required some effort to implement the processor support, where the 
KA610 MicroVAX I series then kicked off the so-called subset VAX systems; those 
newer VAX systems that lacked various architectural mechanisms from the earlier 
VAX-11 series including the PDP-11 instruction set.

I'd expect that the initial approach used for development here was to load a 
MicroVMS or VAX/VMS disk image into an emulation that presents itself as a 
VAXstation 2000, and booting it.  The version would have to be new enough to 
support the VAXstation 2000 hardware.  
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