"8253 PIT - Recently rewritten after microcontroller-based research. At least one previously undocumented feature discovered. Accurate enough for PCM audio."
// If the counting element was reloaded between load of LSB and MSB, it is an incomplete load.
// Reload the counting element again when we get the MSB.
// Note: This is completely undocumented behavior
The author has done a superb job here. Not only does it have a cycle-exact Intel 8088 implementation (matched with disassembled microcode timings and hardware-verified) - it does the same for the CGA, where the dot clock is 3 times the CPU clock frequency... and it correctly represents the monitor's output, overscan included, which most other PC emulators have never bothered to do.
And those debugging tools are something else, too!
My first computer was a hand me down IBM XT. No hard drive, but two 5.25 floppy drives. I never tried running The Secret of Monkey Island on it, but it did run games like Night Mission Pinball. Paratrooper. and JBIRD.
There seems to be an issue with keys such as !"£$%%^&*():{} with this emulator, I can't even type in D: to change drive as the colon does not get sent. It might be that I am on an UK keyboard? Otherwise, it works very well, if a bit slowly.
By definition, all Atari 2600/VCS emulators are cycle accurate.
That machine required very precise timing of the CPU to drive the video output.
There are a number of other cycle-accurate emulators, including some you woudln't expect, like a cycle-accurate emulator for the C64 floppy disk (needed for anti-piracy and some high-end demos that use the floppy like a co-processor).
For the uninitiated, the Commodore 1541 (and later 1570) are external floppy drives that contain their own 6502 CPU and work RAM. In fact, you could daisy-chain two of them with a C64, tell one to copy a whole disk from the other, and disconnect the C64; the drives would continue to work as they do not rely on the C64 at all.
The "C64" demo "Freespin" wires the drive's data cable directly into the monitor's data cable to play a demo (including audio!) without an actual C64 involved at all:
"8253 PIT - Recently rewritten after microcontroller-based research. At least one previously undocumented feature discovered. Accurate enough for PCM audio."
... and it turns out that it's this ...
https://github.com/dbalsom/martypc/blob/main/core/src/device...