The concept of the "main cycle" of the emulator.

The basic concept behind the emulator is to mimic the functions of the older computer's hardware components. This doesn't mean it replicates the exact hardware physically. Instead, it simulates the behavior of the hardware using software. It can emulate the function of processors, memory, graphics units, I/O systems, etc.

Since the hardware components run in parallel, the emulator must run a small portion of the code and update the simulation of the input/output virtual components.

What I usually do is make the main cycle duration of the emulator exactly the time of a frame video of the CRT monitor. This mimics the way vintage computers were programmed.

I could summarize the main cycle of the emulation into steps:

• Run CPU.  
• Run Graphics unit.
• Run Sound unit.
• Run input/output unit.
• Update audio/video.

Each step must perform the same operations performed by the real hardware in the amount of time that we decide. We need to calculate it, so Jarvis, are you awake?

How long is a frame in the video signal generated by the Macintosh 128k?

Calculating the duration of a frame in the video signal generated by the Macintosh 128K requires knowing technical specifications such as the monitor's refresh rate or other specifications relating to the timing of the video signal. However, I was unable to find this precise information in the documents consulted.

Without the exact specs of the Macintosh 128K monitor, I can't provide an accurate value. If you have additional questions or if I can assist you in any other way, please let me know.

This is not good. I think that it will be difficult to find the specific timings of the CRT monitor embedded in the Macintosh 128K. I think it's better if I search for those data personally by hand.