I am running Ubuntu 18.04 on a 2006 iMac with 3GB RAM and Core2Duo processor. I want to upgrade to Ubuntu 20.04.6 but was informed that I needed to do a fresh install. So I created a bootable CD using a different Linux machine and attempted to boot using the Apple SuperDrive that is built in to the device.
It didn't want to boot and instead I was presented with the grub menu so after doing a bit of research I performed some edits via the grub command line, using the GRUB manual for reference to locate the linux root filesystem and modify it as follows:
grub> set root=(hd2,gpt2) grub> linux /boot/vmlinuz-4.15.0-210-generic root=/dev/sr0 grub> initrd /boot/initrd.img-4.15.0-210-generic grub> boot
When I hit enter after "boot" the screen went blank and nothing at all happened. So I tried to reboot, using the Alt key to bring up the boot loader. It shows:
1.
2. Select CD_ROM Boot Type :
However at this point the keyboard stops communicating and no inputs are accepted. I have tried the trick of pressing either "1" or "2" and Enter as it is booting, and that succeeds in registering the numeral after "Boot Type" but, again, no action is taken and the keyboard stops being effective.
At this point the CD is stuck in the SuperDrive and I have no way to eject it. I have tried rebooting repeatedly, and even uplugged the computer completely and then plugged it back in, but it won't budge past this point.
What else can I try to get a response from the boot loader?