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Showing posts from June, 2021

8-bit CPU: Display updates

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The display module turned out quite nice, but there were some flaws I wanted to fix. In order to connect the module to the Computer, some additional hardware has to be added as well. Flicker I noticed that with a corner of an eye I can catch some flickering, but when I at it directly, it appears to be fine. Ben used 10 nF capacitor and 100 K resistor with 555 timer. I had no 100 K resistor, so I used 330 K instead. If we put the values in NE555 calculator , it gives around 218 Hz. Each display switches 4 times slower, resulting in 54 Hz. My eyes have always been sensitive to flicker, I remember when old CRT monitors gave me headaches with their 60 Hz. After short consideration I replaced it with 10 K resistor. It pushes up the frequency to almost 7 kHz. While this may feel as an overkill, all chips are rated for much higher frequencies than that. And now there definitely is no visible flickering. Mode indication I found out that it is a bit confusing not to know in which mode ...