I have the Phoenix version of this already. The Ralf Brown Interrupt List is also very relevant and vendor-neutral, as well as including some normally-undocumented stuff, if you're interested in low-level PC programming.

I should know the answer to this, but was using the BIOS the only way to interact with hardware like disks, mice, and keyboard?

I remember copying code to make wrappers for those in C from books but can't remember if that was the only option or...

I know with VGA you had to use the BIOS to set modes but you could just write to the memory which was mapped at a certain address

Phoenix CBIOS:

https://bitsavers.org/pdf/ibm/pc/ps2/bios/CBIOS_for_IBM_PS2_...

Phoenix ABIOS:

https://bitsavers.org/pdf/ibm/pc/ps2/bios/ABIOS_for_IBM_PS2_...

I thought this was something to do with the Amiga

Back in the day, there was a website called amihotornot.com, where people could post photos of themselves and others could vote on how good they look.

This spawned a variety of copycat sites, all using the amiXornot name template. My favourite was amibiosornot.com, which showed you a photo of a PC motherboard, and asked: AMI BIOS or not?