3 ms·
>It's weird the front page does not mention but 86box (and pcem from which it forked) is a cycle accurate emulator. because it isnt. While hacking around to de
by rasz 4y ago
>It's weird the front page does not mention but 86box (and pcem from which it forked) is a cycle accurate emulator.
because it isnt. While hacking around to debug cache mod I patched bios to output my custom codes using POST card display https://github.com/raszpl/430FXL2Cache https://github.com/raszpl/430FXL2Cache. My code wouldnt work on real hardware for the longest time until I figured out 86box is really bad at timing. Something that runs at 1 per second IRL runs at hundreds of hertz in emulator, and vice versa depending on what you are going (accessing I/O).
https://www.vogons.org/viewtopic.php?p=1125370#p1125370 https://www.vogons.org/viewtopic.php?p=1125370#p1125370
Turns out some real POST cards dont love the idea of writing to port 0x80 twice in a row without any delay and will Error out of hang whole computer. 86Box on the other hand hard links writes to 0x80 with its graphical output update routines and hammering that port not only slows down emulation, but can hang whole emulator so hard you cant even close it until reaching Program Not Responding Timeout.