
0xB8000 is the base address for the CGA video buffer on a 1980s era PC. 0xB0000 was for MDA (eg, a Hercules card).
MDA's memory range didn't overlap with CGA, EGA, or VGA, so dual-head systems were possible, eg, program display on the color display, debugger in the monochrome display.
My go-to book for the internals, with all sorts of numbers like the above, was "The Peter Norton Programmer's guide to the IBM PC", available at https://archive.org/details/peternortonprogr00nort .
For example, philipswood at https://news.ycombinator.com/item?id=28053235 pointed out the IBM PC timer interrupt was 18.2 ticks per second. Norton explains that at https://archive.org/details/peternortonprogr00nort/page/148/... - the main clock, the 8284A, oscillates at 1,193,180 times per second. The clock interrupt is every 65536 oscillations = 18.20648... ticks per second. And 1,193,180 * 4 = 4.77 MHz.
Decimal 27 = hex 1B is a number I associate both with writing ANSI escape codes (still useful today), and with writing printer commands to my Epson MX-80, like setting to quad density mode for higher quality output. With 9-pins it could make very nice graphical printouts.
300, 1200, and 2400 baud were important modem speeds in my era. The earlier Bell 101 era used 110 baud.
From that scene in Hackers where they were listing off books with nicknames (ex. Compiler: Principles, Techniques and Tools, aka "The Dragon Book," I ended up being curious about what other books might also have the same treatment. This is the current list I have, scoured from places like Wikipedia, Amazon and other forums, but I wondered if anyone found anything else? (This is just for my own curiosity)
The AWK Programming Language, Alfred Aho, Peter Weinberger, Brian Kernighan, aka "The Gray Book"
The C Programming Language, Brian Kernighan and Dennis Ritchie, aka "The White Book"
Compilers: Principles, Techniques and Tools, aka "The Red/Purple Dragon Book"
Computer Architecture: A Quantitative Approach, aka "The Pillar Book"
The Design and Implementation of the FreeBSD Operating System, aka "The Devil Book"
Foundations of Computer Science, Aho, Alfred and Ullman, Jeffrey, aka "The Turtle Book"
Introduction to Automata Theory, aka "The Cinderella Book"
Lions' Commentary on UNIX, 6th Edition, aka "The Lions Book"
Modern Compiler Implementation in ML, aka "The Tiger Book"
Operating Systems: Three Easy Pieces, aka "The Comet Book"
The OpenGL Programming Guide, aka "The Red Book"
The Peter Norton Programmer's Guide to the IBM PC, aka "The Pink Shirt Book"
Principles of Compiler Design, aka "The Green Dragon Book"
Programming Perl, aka "The Camel Book"
Programming Ruby, aka "The Pickaxe Book"
Smalltalk-80: The Language and its Implementation, aka "The Blue Book"
Structure and Interpretation of Computer Programs, aka "The Wizard Book"
Unix Power Tools, aka "The Unix Book"