I had a giant pink book of PC BIOS that was my bible from 1988 to 1994 before the internet took off. I can't for the life of me remember who published it, but it had everything you needed to know about PC BIOS and an old IBM bios source listing. It was over 600 pages.

It look liked this 1200 page book, but this isn't it (also a book I used):

https://www.amazon.com/PC-Interrupts-Programmers-Reference-T...

I also had the Apple ][+ ROM listing in one of those spiral-bound books from apple circa 1980 but that too has been lost, sadly.

Sounds like the The Programmer's PC Sourcebook (which is on my shelf, and yes, one could say it has a pink cover).

YES! That is exactly it. I wish I saved mine for nostalgia.

We had something like this but it was a four-inch thick printout on green-bar paper and nobody knew where it came from.

e.g. https://archive.org/details/bitsavers_ibmpcpc602renceAug81_1...

https://sites.google.com/site/pcdosretro/ibmpcbios has the source code for various models typed.