Hi, 
I got 20000620-1.5 installed on PowerMac 7500 + 604e/160.
The Open Firmware version is 1.05.
Almost eveything is fine, except
 -- ignores existing disklabel
 -- I need to change real-base number at OF
 -- newfs at sysinst shows 3 times large MB numbers
 -- unable to change root passwd:

Then whole story is:

(1) make boot floppy at another NetBSD/i386 box with
dd if=boot.fs of=/dev/rfd0a bs=64k

(2) > boot fd:0

(3) scan order for internal or external
    It scans external first, this makes a little bit
   confusing because internal is always there but external
   one is easy to be connected/disconnected and not necessarily
   giving the same sd number to the internal one.
   ( This is not 1.5 specific though,)

(4) run sysinst
   I did manually partition like ( in CYL numbers)
      size start
   a   100    0    /                50M
   b   300  100    swap            170M
   c  3707    0                
   d   308  400    /usr            170M
   g  3000  708    /mount_union  1.7G

(5)  partition size shown at newfs
     The disk size shown at newfs seems to be too big.
   I think about 3 times.
   I have used HP 2G disk connected to the external SCSI
   port.

(6) ignores existing disklabel
    sysinst of macppc ignores the existing partion.
   ( at fresh install). I think NetBSD/sparc honors the
   existing partition.

(7) boot with the command  > boot scsi/sd@2:0
   It stops like
----------- 
>> NetBSD/macppc OpenFirmware Boot, Revision 1.2
>> (tsubai@moeko, Sun Feb  6 23:24:18 JST 2000)
2771516+228288 [100+101888+85618/
----------- 
   This hard copy is not the one with recent alpha,
   instead with 20000606 and with StarMax. But thing is
   very much similar at this time.

   Tsubai san suggested Kernel loads extending over
   the OF area which some model uses location at 4M,
   start(1M) + kernel size(3M+) > OF area (4M)

(8) I typed at Open Firmware as
  > setenv real-base F00000
  > reset-all
  > boot scsi/sd@2:0

   Then I got single user boot

(9) At single user, when I type ed /etc/rc.conf,
   /tmp/ed.....    is read-only file system.

   So I need to mount -a before doing so.

(10) After multi user booting,
  with root, when I typed passwd, I got

  passwd: failed to parse principal.
  Configuration file does not specify default realm.
 
  So I am running it with no root passwd :-) now.

That's the story so far,

Thanks Matt, Tsubai San, and all macppc folks,
---
Makoto Fujiwara