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It's weird the front page does not mention but 86box (and pcem from which it forked) is a cycle accurate emulator. This is the most important difference from DO

by chx 4y ago

It's weird the front page does not mention but 86box (and pcem from which it forked) is a cycle accurate emulator. This is the most important difference from DOSBox which does not even intend to be one. It's overall a lower level emulator, it needs a BIOS which DOSBox doesn't. All this means a comparison is hard between the two.

pygy_ 4y ago
Indeed, DOSBox has been written for DOS games (and it's great at this), compatibility with other software has never been a concern. BIOS and DOS calls are HLEd which is why neither are necessary to get it running.
dark-star 4y ago
86box is not at all cycle accurate. It's LLE, yes (as opposed to DosBox which is HLE), and the devs try to make the CPU as cycle-correct as possible, but that hardly means that the whole emulator and all devices it emulates are cycle-accurate
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.

by chx 4y ago

pygy_ 4y ago

Indeed, DOSBox has been written for DOS games (and it's great at this), compatibility with other software has never been a concern. BIOS and DOS calls are HLEd which is why neither are necessary to get it running.

dark-star 4y ago

86box is not at all cycle accurate. It's LLE, yes (as opposed to DosBox which is HLE), and the devs try to make the CPU as cycle-correct as possible, but that hardly means that the whole emulator and all devices it emulates are cycle-accurate

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.