Michael L. Hitch said:
> 
>   Argh!  Try this change and let me know if it works.
> 
> Michael

[ diffs deleted]

I used this to be able to boot my 5000/200. Looks very close to your diffs :)
I was about to send a PR for this, and a few other things, but I didn't find
the time ... 

Index: dc.c
===================================================================
RCS file: /usr/cvs/cvsroot/sources/src_current/sys/arch/pmax/dev/dc.c,v
retrieving revision 1.1.1.6
diff -c -r1.1.1.6 dc.c
*** dc.c	1996/05/30 21:08:30	1.1.1.6
--- dc.c	1996/06/13 07:37:40
***************
*** 214,230 ****
  	static int nunits = 0;
  
  #if NTC>0
! 	if (parent->dv_cfdata->cf_driver != &mainbus_cd &&
! 	    strcmp(d->iada_modname, "dc") != 0 &&
! 	    strcmp(d->iada_modname, "mdc") != 0 &&
! 	    strcmp(d->iada_modname, "dc7085") != 0)
  		return (0);
  	else
  #endif
! 	if (strcmp(ca->ca_name, "dc") != 0 &&
! 	    strcmp(ca->ca_name, "mdc") != 0 &&
! 	    strcmp(ca->ca_name, "dc7085") != 0)
! 		return (0);
  
  	/*
  	 * Use statically-allocated softc and attach code until
--- 214,234 ----
  	static int nunits = 0;
  
  #if NTC>0
! 	if (parent->dv_cfdata->cf_driver != &mainbus_cd) {
! 	    if ( strcmp(d->iada_modname, "dc") != 0 &&
! 	         strcmp(d->iada_modname, "mdc") != 0 &&
! 	         strcmp(d->iada_modname, "dc7085") != 0) {
  		return (0);
+             }
+ 	}
  	else
  #endif
! 	{
! 	    if (strcmp(ca->ca_name, "dc") != 0 &&
! 	        strcmp(ca->ca_name, "mdc") != 0 &&
! 	        strcmp(ca->ca_name, "dc7085") != 0)
! 		    return (0);
!          }
  
  	/*
  	 * Use statically-allocated softc and attach code until

--
Manuel Bouyer, LIX, Ecole Polytechnique
email: bouyer@lix.polytechnique.fr
--