I also had problems with the boot floppy, it hung at 'root file system type: ffs'. My setup is similiar to yours: 486SX 33, 260 MB HD, 4MB Ram, NetBSD 1.3.3 boot.fs. 
After some experimenting I came to the conclusion that 4 MB of memory was the problem. The Boot Floppy booted fine when I put an extra 8 MB of memory in the machine. Apparently, 4 MB is not enough to hold the initial ramdisk.

/Martin Johansson




> From port-i386-owner-martin=st.se@netbsd.org Wed Apr 21 08:15:08 1999
> X-Authentication-Warning: cynic.anim.dreamworks.com: abs owned process doing -bs
> Date: Tue, 20 Apr 1999 23:07:44 -0700 (PDT)
> From: David Brownlee <abs@anim.dreamworks.com>
> To: James Webster <james3838@tsi-net.com>
> cc: port-i386@netbsd.org
> Subject: Re: Boot Floppy Hangs
> MIME-Version: 1.0
> Sender: port-i386-owner@netbsd.org
> Delivered-To: port-i386@netbsd.org
> 
> 	Is one attached via isa and the other via isapnp?
> 
> 	If so, it has _just_ been fixed in 1.4_BETA :)
> 	You should try the next snapshot of 1.4_BETA if you can - it
> 	should be announced RSN on this list...
> 
> 		David/absolute
> 
>                       Neighbours should be one of:
>                 a) Understanding   b) Distant   c) Deaf
> 
> On Tue, 20 Apr 1999, James Webster wrote:
> 
> > I needed a spare system to run some tests on, so I grabbed an old unused 486 off the shelf and put together parts to make a new system.  Nothing fancy, though the hard drive I threw on it had Win95 (which actually booted, which indicates to me there can't be a serious hardware problem).  
> > 
> > My problem is, when I boot using the 1.3.3 (and 1.3.2) boot.fs it hangs at "root file system type: ffs".  The only thing odd that I noticed was that it detected my 3Com 3C509B twice.  Once as ep0 (irq 15) and once as ep1 (irq 5).
> > 
> > The last four lines listed are:
> > 
> > md0: internal 1537k image area
> > boot device: fd0
> > root on md0a dumps on md0b
> > root file system type: ffs
> > 
> > This is a generic 486DX2 66 machine, with a 216MB HD, 4MB Ram, and two ethernet cards (3c509B and NE2000 compatible).
> > 
> > Thanks for your help,
> > James
> > 
> 
>