[ ... not a DECstation question ... ] 

>>   I have a NetBSD-1.4/i386. What I did:
>> 
>>       # fdformat -C 160
>>       # disklabel -W /dev/rfd0c
>>       # gunzip -c /NetBSD-1.4.1/pmax/installation/diskimage/diskimage.gz |
>>               dd of=/dev/rfd0c bs=10240
>> 
>>   I got this:
>> 
>> dd: /dev/rfd0c: end of device
>>  0+301 records in
>>  0+300 recored out
>>       1228800 bytes transfered in 39 secs(31507 bytes/sec)
>> Broken pipe
>> 
>>   What's wrong?
>
> 1228800 == 1200 * 1024 - sounds like an old 1.2MB 5 1/4" floppy.

For 3.5" floppy disks, 'bs=18k' or  'bs=9k' are magic numbers to expediate
the write performance.

Tohru Nishimura
Nara Institute of Science and Technology