The kernel finally built and booted first time! My changes to the 21-Jan sys 
tar files were:

% diff -c -2 cons.c cons.c.old
*** cons.c      Sun Jan 22 23:06:17 1995
--- cons.c.old  Sun Jan 22 23:01:15 1995
***************
*** 73,85 ****
  };

! cnopen(dev, flag, mode, p)
        dev_t dev;
        int flag, mode;
        struct proc *p;
  {
        if (cn_tab.cn_dev == NODEV)
                return (0);
        dev = cn_tab.cn_dev;
!       return ((*cdevsw[major(dev)].d_open)(dev, flag, mode, p));
  }

--- 73,86 ----
  };

! cnopen(dev, flag, mode, p, fp)
        dev_t dev;
        int flag, mode;
        struct proc *p;
+       struct file *fp;
  {
        if (cn_tab.cn_dev == NODEV)
                return (0);
        dev = cn_tab.cn_dev;
!       return ((*cdevsw[major(dev)].d_open)(dev, flag, mode, p, fp));
  }

***************
*** 168,172 ****
        /* check to be sure device has been initialized */
        if (cn_tab.cn_dev == NODEV || cn_tab.cn_disabled)
!               return ((*callv->_getchar)());
        return ((*cn_tab.cn_getc)(cn_tab.cn_dev));
  }
--- 169,173 ----
        /* check to be sure device has been initialized */
        if (cn_tab.cn_dev == NODEV || cn_tab.cn_disabled)
!               return ((*callv->getchar)());
        return ((*cn_tab.cn_getc)(cn_tab.cn_dev));
  }
***************
*** 182,186 ****
        if (cn_tab.cn_dev == NODEV || cn_tab.cn_disabled) {
                s = splhigh();
!               (*callv->_printf)("%c", c);
                splx(s);
        } else if (c) {
--- 183,187 ----
        if (cn_tab.cn_dev == NODEV || cn_tab.cn_disabled) {
                s = splhigh();
!               (*callv->printf)("%c", c);
                splx(s);
        } else if (c) {




% diff -c -2 fb.c fb.c.old
*** fb.c        Sun Jan 22 23:09:46 1995
--- fb.c.old    Sun Jan 22 23:09:19 1995
***************
*** 737,741 ****
        } else {
                s = splhigh();
!               (*callv->_printf)("%c", c);
                splx(s);
        }
--- 737,741 ----
        } else {
                s = splhigh();
!               (*callv->printf)("%c", c);
                splx(s);
        }



My system is a DECsystem 3100 with 24Mb of memory and a RZ24 system disk. These 
are the boot messages:

Copyright (c) 1982, 1986, 1989, 1991, 1993
        The Regents of the University of California.  All rights reserved.

NetBSD 1.0A (NETBSD) #0: Sun Jan 22 23:14:28 GMT 1995
    root@netbsd.uvo.dec.com:/usr/src/sys/arch/pmax/compile/NETBSD
real mem = 25165824
avail mem = 20918272
using 614 buffers containing 2514944 bytes of memory
cpu0 (MIPS R2000 revision 2.0)
fpu0 (MIPS R2010 revision 2.0)
data cache size 64K inst cache size 64K
dc0 at nexus0 csr 0xbc000000 priority 2
pm0 (monochrome display)
le0 at nexus0 csr 0xb8000000 priority 1 ethernet address 08:00:2b:14:1d:69
sii0 at nexus0 csr 0xba000000
rz0 at sii0 drive 0 slave 0 DEC RZ24    (C) DEC rev 4041, 409792 512 byte blocks
rz1 at sii0 drive 1 slave 0 DEC RZ23L   (C) DEC rev 2528, 237588 512 byte blocks
rz4 at sii0 drive 4 slave 0 DEC RX23    (C) DEC rev 0054, 0 0 byte blocks


Stephen.
     _____________________________________________________________________
   //                                                                     \\
  //  Stephen Carpenter               "One inode short of a file system"   \\
 //                                                                         \\
 \\   UNIX Guru                                sac@uvo.dec.com              //
  \\  Digital Equipment Corporation                                        //
   \\_____________________________________________________________________//