Booting an older RS6000 off cdrom

Hi all I am in the process of finishing my spring cleanup and I am giving a RS6000 7012 320H powerserver its very last chance to see if I can get it to do anything usefull. I think I have mentionned this machine here before, still I am looking for some help on this. The machine is probably all ok. It was booting of the HDs with the original AIX when I got it and still will boot with the diags floppy disks for RS6000 and I can "talk" to it from a terminal connected to the 1st serial port....The HDs were taken out a bit later and the machine was left sitting in a corner for a long time. Machine has 80 Megs RAM, SCSI card...the hardware is acting ok. I dont have the keyboard, graphics card or monitor so I am woking this thing from the terminal connected to the serial port. I have AIX on 2 cd's they say ENTRY SERVERS R4.2.1. I checked on my Linux box and the files are there and the cds are readable. I have connected a Pionner DR-706S drive on the SCSI chain and also added one of the original HDs (was flushed of original AIX and used somewhere else) with a different ID on the chain. Chain is terminated at the end. I am trying to get this thing to do something usefull by re-installing AIX. I cant get it to boot AIX and install off the CDrom. I tried the CDrom at ids 5 and 6 (suggested in some AIX newsgroup posts for similar situations) The CD is configured for 512 byte block size... its a Pionner. I know that some CDROMs will not boot these RS6000 but is the only issue the block size? I have heard that Plextors, Pionner and original IBMs will boot these Rs6000. I have older toshibas and DEC that should support 512 blocks, should l I try these or its hopeless? I did put the machine in service mode...I did try to disconnect the battery to reset the bootlist. What is happenning now with HD and CDROM connected is machine goes through post and displays 253 then looks like it goes into a never ending loop of resetting the SCSI bus about every 2 or 3 minute or so. I can see the leds on both the HD and the cdrom flicker (cdrom also spins up and led flashes briefly every 2 -3 minutes or so) so I am suspecting that the RS6000 is seeing something on the SCSI bus and the machine is looking for something to boot with. I suspect it sees the devices because without the HD connected, it will go through post and then the floppy led will flash every few seconds waiting for the boot/diag floppies. I suppose it does not see any SCSI devices so it abandons booting from those and expects some floppies... The Pionner CDROM alone on the SCSI chain will result in the machine expecting floppies...so now I wonder if the CDROM is being seen at all... Ideas anyone? Thanks Claude http://computer_collector.tripod.com