Full details on the boot procedure and examples are contained in Appendix H of this manual.
Loading a system from disk involves almost all of the parameters in the ffbusc string. You do not have to be concerned with the file number unless you are loading hardware diagnostic programs for sequential execution. The file number can be defaulted to 0 (no offset).
For the bus address, specify the HPIB/SCSI address, in the range of 0 to 7, of the disk drive that contains the system file.
If you are booting from an HP 7902 disk drive, set the unit/head parameter to 0 to indicate the left drive, 1 to indicate the right drive.
If you are booting from a CS/80 disk set the unit/head parameter to 0.
If you are using an HP 7906 drive, set the unit/head parameter to the number of the head that will read the system file.
If you do not specify the ffbusc[file] string, the VCP/loader ROM assumes a default string of either 2027<defaultfile> for booting from HPIB disk or 6027<defaultfile> for booting from SCSI disk. This loads the default file from the disk LU that starts at head 0, cylinder 0, and sector 0 of the disk drive that has bus address 2 on the HPIB connected to select code 27, or has bus address 6 on the SCSI connected to select code 27.
The boot extension (BOOTEX) should reside at the beginning of that disk. The VCP/loader ROM loads that file into memory and executes it.
What happens next depends on what file you specified in your boot string. If the file is a type 1 file, BOOTEX assumes it is a system file, loads it into memory, and executes it. If the file is a type 4 file, BOOTEX assumes it is a boot command file and follows its instructions for booting. If BOOTEX cannot find the file you specified, it goes into interactive mode and prompts for boot instructions. To supply the boot instructions interactively, use the same commands contained in the boot command file as described previously.
If you do not specify a file, BOOTEX looks for the file named /SYSTEM/BOOT.CMD, or SYSTEM if the LU is a FMGR cartridge. If the file is a type 1 file, BOOTEX assumes it is a system file, loads it into memory, and executes it. If the file is a type 4 file, BOOTEX assumes it is a boot command file and follows its instructions for booting. If BOOTEX cannot find either of these files, it goes into interactive mode and prompts for boot instructions. After you have entered your boot string, press RETURN to boot your target system. After your target system boots, check to see that it is running. There are no standard tests for this; just execute a few commands to convince yourself that the system is operating as it should.
If your system does not work properly, or if it does not boot at all, you must go back to the host system and start over again. If the error is in the partition structure or in one of the programs, modify your boot command file (if you used one) and try booting the target system again. If the error is more fundamental, regenerate your system using RTAGN and then start the installation process from the beginning.
DiskBased System Installation Procedure 917