I don't need to pass -D${MACHINE}.   What I need to pass is
-I../../sys/arch.   I'm just using the same piece of code that the 68k
uses rather than defining new code specifically for the pmax.   If you
wanted, you could apply this change instead:

RCS file: /a/cvsroot/src/usr.bin/vmstat/Makefile,v
retrieving revision 1.13
diff -c -r1.13 Makefile
*** Makefile    1994/12/28 18:39:53     1.13
--- Makefile    1995/05/05 01:20:32
***************
*** 5,10 ****
--- 5,13 ----
  .if (${MACHINE_ARCH} == "m68k")
  CFLAGS+=-D${MACHINE} -I${.CURDIR}/../../sys/arch
  .endif
+ .if ${MACHINE} == "pmax")
+ CFLAGS+=-I${.CURDIR}/../../sys/arch
+ .endif
  MAN=  vmstat.8
  BINGRP=       kmem
  BINMODE=2555

I would be genuinely thrilled to have the time to spend making this
code right - I'm not even sure what it's trying to do, or why it's not
needed on other architectures.   Maybe this will fall out when we make
the switch to config.new.   In any case, right now vmstat doesn't
compile on the pmax, and I believe this is a bug worth fixing in the
short term, and then revisiting when time permits.

			       _MelloN_