Was your disk shipped with a GPT partition table?
Then change it (re-partition) to MBR.
I don't have a another computer that runs Unix and if there is a command at boot, I don't know what it is.
I am out of the office today, but I think I have a solution.
Can you build a new system that has a PCI slot for a SCSI host adapter.
Install Linux Mint 21.3 and virtual box 6.1
Presumably you will use a SSD for the disk .
To install virtual box: select system administration, then software manager, type in virtual box and select VB then click install.
Send me your sco license info and how you want the disk partitioned. I will send you a VM to restore
Do you know if your backup tapes were created with tar or cpio?
I don't think that the SCO 5.0.4 CD is bootable, however, floppy images for BOOT and ALAD (SCSI driver for some Adaptec chipset) are present on the CD under the IMAGES directory. Look for files 1.44MB in size.
You can put the CD in a different system and create the two 1.44Mb 3 1/2" floppies using suitable imaging utilities to allow you to boot and possibly continue installation from the CD drive.
Wouldn't matter, the installation routine can be instructed to erase the contents of the disk, run fdisk and divvy. The fact that the install does not find a disk is the problem. Possibly because the disk controller, or motherboard was damaged during removal or installation of the new disk. Or possibly because the jumper settings on the drive do not match the CMOS settings.
When I try to fdisk at the boot: prompt I get fdisk not found. I tried also on a working computer with the N1 and N2 floppies and get the same result, that fdisk not found. Are my floppies bad? Because if I don't call out fdisk they load fine until it can't find the hard drive. Any one know were I can get a copy of the N1 & N2 disks for SCO 3.0.0?
There's no way that 'fdisk' will be available at the boot: prompt.
At this point, the system has simply read the boot blocks from the floppy (or CD if you're booting from CD media) and stops to allow modification of the boot environment, e.g. loading a different hard disk driver (SCSI, IDE, SATA or whatever). Your hardware is very old so the default drivers in the distro may well not be compatible so you may need to load a specific driver using the 'defbootstr' command. Such a command allows you to load a driver from other media, e.g. inserting a different floppy with the required driver temporarily.
Yes, probably fsck.technology
but it's likely that the floppies that you have are fine. It would not start the install routine up to not recognising the HD if they were corrupt. I would expect a read error shown if that were the case. As @jgt has already said, fdisk and divvy (the SCO disk partitioning utility) would be run automatically by the install routine once it can see the hard drive.
Further to my May 22nd post:
You need only attach the tape drive to the Linux partition as the Linux versions of tar and cpio are capable of reading a tape created by a Unix system. Then it is possible to restore the tape data to the Linux partition, then use scp to copy that data to the SCO virtual system.
After which all you need to do is add your users and printers.