I’ve found multiple manuals such as the pic and few others like PIC8259 on the internet. They all come with just a few pages, but the paging seems that they are from a whole datasheet/book/manual which has all of them. I’m saying that like this one, I got page 6-91 to 6-105, so where are the other pages?

Please provide the book/datasheet/manual name and link if you know, or any clue that could help me. Thanks a lot!