How compatible were "MS-DOS Compatible" machines?

Chuck Guzis wrote: I did, trying to code for the aforementioned "PC compatible" project. I was trying to write a keyboard handler and things were just completely going south. I finally dredged up some documentation that showed me where the BIOS entry point was for the keyboard routine (I tried following the pointer at Int 9 but I got confused because it doesn't point directly there), and disassembled it -- turns out I wasn't properly acknowledging the keyboard "break" code or something. So I needed the docs, which pointed me to code, which pointed me to the answer. Something was still screwy, so in the end I ultimately did this: - Hook INT 9 - read the scancode out of port 60h - PUSHF - call the old keyboard handler to properly acknowledge the keystroke (let the BIOS clean up the mess! Plus I figure this is a way to increase my compatibility) - alter 0040:0017 (or wherever it is, don't have code in front of me) to empty the keyboard buffer by setting queue head = queue tail So far, it's working perfectly (crosses fingers). -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/