DS20E, Alpha Core 1.0 and CentOS 4.2 installers do not boot

[K Hanai]

Hi,

I am new to alphas.
I am trying to install AC 1.0 or CentOS 4.2.
But both the installers do not boot.
AC 1.0 displaying (last few lines)

iso: First datazone: 29 Root inode number 59392
aboot: loading compressed /kernels/vmlinux.gz
 unzip: unknown compression method
aboot: loading uncompressed /kernels/vmlinux.gz
aboot: read returned 0 instead of 8 bytes
then aboot prompts.

in the case of CentOS4.2,
iso: First datazone: 28 Root inode number 57344
aboot: loading compressed /kernels/vmlinux.gz
aboot: zero-filling 2862456 bytes at 0xfffffc00018d3870
aboot: loading initrd (5355113 bytes/ 5229 blocks) at
0xfffffc00ff958000
aboot: read returned 0 instead of 5355520 (5230 * 1024) bytes
then aboot prompts.

My machine is DS20E (SRM firmware the latest 7.0) dual 667 MHz
cpus with 4 GB RAM. ac2-qboot1.iso does boot, then I am expecting
AC 2.0.

Thanks
K. Hanai