True, but… When MBR Grub drops to rescue or doesn’t appear at all, it’s not only difficult (at least for newbies) but somewhat random if you can actually boot a given OS. With EFI Grub, I’ve often managed to boot using BIOS boot override to launch a usable Grub configuration.
Actually grub 0.x series had much more useful rescue shell tab completion than the latest release. You could easily list all boot devices, partitions, and even filesystems and their contents. All from the rescue shell. Consequently, you could boot into Linux and reinstall grub in the MBR to fix it. All that without using a boot CD/USB! Good luck doing that with the latest version of grub and UEFI.
Also getting into the BIOS on legacy firmware was also very simple. On most machines it’s the three finger salute followed by either F1, Delete or rarely F11 or F12.
The boot process was simple, and the BIOS had just one simple task: load and execute the first 512 bytes of the disk that was designated as the boot device. That’s it.
Asus --> Del - Enter BIOS, F8 - Boot menu (very confusing since Windows also uses F8 for the recovery mode boot menu, so you have to press F8, then when the boot menu appears, chose the boot device, then have one hand on Enter and the other on F8 again, so that you hit Enter and start tapping like crazy on F8 to enter the rescue mode menu... annoying as hell)
GigaByte --> Del or F2 - Enter BIOS, F12 - Boot menu, Alt + F10 - Copy main BIOS to backup BIOS
MSI --> Del or F2 - Enter BIOS, F11 - Boot menu
ASRock --> Del or F2 - Enter BIOS, F11 or F10 - Boot menu
Biostar --> Del - Enter BIOS, F9 - Boot menu
Intel --> F2 - Enter BIOS, F10 or F12 - Boot menu
I used to remember some of the brand name PCs as well, but time has gotten the best of me 🤷.
The boot process was simple, and the BIOS had just one simple task: load and execute the first 512 bytes of the disk that was designated as the boot device. That’s it.
This is actually what I love about MBR nowadays. It's simple enough so no one wants to mess with it and render the rig unbootable and obscure enough so no one (MS) actually checks if there is anything there that might trigger warnings (non-MS code).
