I also had problems with a IBM 0661 disk.  I was unable to get it to 512
byte sectors from 524/sector using either RZDISK (VMS) or TEST 75 on my
3100-M76. 

I was able to format it on my RS/6000-220 using the diag program's service
aids/disk media service aid/format disk option in AIX.

Although there were no command parameters and no information from AIX on
what is was doing, when it was done the disk was reformatted to 512 bytes
and I was able to use the disk on the VAX and later make a spare bootable
unix system disk on my DEC mips machine.

Perhaps the IBM format also turned off the "target initiated sync
negotiation" for AIX in the saved config code page in the drive.

Paul


 On Mon, 20 Mar 2000 jkunz@unixag-kl.fh-kl.de wrote:


> > Run the PROM based formatter on the drive using "TEST 75" to the
> monitor. I never did this and had no problems connecting various disks
> from Fujitsu, Seagate, Quantum, IBM (including a 1,8GB 0664), ... to a
> VS3100m76. The only problematic disk I found is the IBM 0661. This
> disk is knowen to be problematic due to the SCSI implementation of the
> firmeware of the disk. (e.g. target initiated sync negotiation)  --