Ensure the SCSI cable is correctly attached. On some adapters, it is possible to put the cable onto the controller backwards. Set boot hard drive to ID6. Put the boot drive at the very end of the SCSI cable. The boot drive must be terminated, either with a Term enable jumper on it, use of terminating resistor packs, or use of an in-line terminator that fits between the cable's drive connector and the drive itself.
Most SCSI adapters provide term power.
All IBM SCSI adapters provide Term Pwr. Use SIMMs that look alike if you can. The memory connectors are bass ackward. The system will not work. Unsupported memory configuration.