J. Seth Henry wrote:

>Here is a clue though:
>
>NetBSD 1.4.1 (GENERIC) #0: Wed Aug 11 04:56:57 CDT 1999
>    fredb@corwin.home:/usr/src/sys/arch/mac68k/compile/GENERIC
>Apple Macintosh Quadra 800  (68040)
>cpu: delay factor 1024
>real mem = 41 943 040
>avail mem = 35 520 512
>using 537 buffers containing 2 199 552 bytes of memory
>mrg: 'Quadra/Centris ROMs' ROM glue, tracing off, debug off, silent traps
>mrg: I/O map kludge for ROMs that use hardware addresses directly.
>mainbus0 (root)

It doesn't appear to be a problem to me.  NetBSD saw 40Meg on boot (real 
mem = 41943040), used about 5Meg for the OS leaving 35Meg for users 
(avail mem = 35520512). The system reserved about 2Meg for I/O buffer 
(537 buffer containing 2199552 bytes).

What makes you think you're only using 20Meg on this system?

-bob