Cnc crt to vga

[moji2107]

Hello. I am really happy that you are sharing your knowledge and experience, and I thank you for that.
I don't have much information regarding image signal processing.
I have some old CNC machinery that uses CRT displays of various sizes, such as 8-inch, 9-inch, and 15-inch (mostly monochrome and some color), and I wanted to convert them to VGA monitors.
The image signal output specifications I have obtained so far are as follows:

• Model 1:
  • Horizontal Frequency (f_h): 25.25 kHz
  • Vertical Frequency (f_v): 55.257 Hz
• Model 2 (in some models):
  • Horizontal Frequency (f_h): 25.0254 kHz
  • Vertical Frequency (f_v): 110.487 Hz
    My guess for the resolution is 720 \times 480.
    Can your method be used to convert these types of signals to standard VGA?
    Or, if there is an issue with memory shortage, could this problem be solved with a Pico 2 and a dedicated code be considered for this purpose?
    I would appreciate it if you could help me on this path.

[scrapcomputing]

Apologies for the late reply.

Model 1 should work. Monochrome (MDA style 1 "color" bit and 1 intensity bit) should work.

Model 2: the vertical refresh rate is 110Hz, so if the resolution is still about the same, it means that the pixel clock is twice as fast. Not sure that the pico (or the pico 2) is fast enough to handle it. You will still get some image from it but it will lower resolution, or more noisy.

As for the resolution limits of Pico 1, sure I would be happy to work with you to support higher resolutions, like 720x480 with a Pico 2, it shouldn't be too hard.

[moji2107]

Thank you for your response. I am currently building the hardware, and after building and testing it, I will definitely share the results with you right here.