On public demand, here are more detailed instructions for booting
NetBSD on SIMH:

1. get
        http://simh.trailing-edge.com/sources/simhv29.zip
        http://simh.trailing-edge.com/sources/vaxpre.zip

2. make a directory to hold the emulator, and unpack both zip files
   there

3. make BIN/vax

4. get
	ftp://ftp.netbsd.org/pub/NetBSD/iso/1.5.2/vaxcd.iso

5. start the BIN/vax program

6. type
        load -r /path/to/simh/VAX/ka655.bin
	set rq0 ra92
	at rq0 netbsd.dsk
	set rq1 cdrom
	at rq1 /path/to/vaxcd.iso
	boot cpu

7. at the VMB prompt, type

        boot dua1:

8. proceed with NetBSD install

9. you may not want to install the X11 stuff

10. I had a problem where the installation program didn't find the
    .tgz files on the cd, so I had to suspend and type

        mount -t cd9660 /dev/ra1a /mnt2

    and resume installation

11. after considerable amount of time later, the installation is
    finished, and you can reboot

12. type 'q' if you want to quit the emulator

13. when you restart the emulator, you may skip the rq1 lines

14. at the VMB prompt, type

        boot dua0:

    to boot off disk

15. Welcome to NetBSD!

-- 
Lars Brinkhoff          http://lars.nocrew.org/     Linux, GCC, PDP-10,
Brinkhoff Consulting    http://www.brinkhoff.se/    HTTP programming