cga monitor

Hello, All I dug up some kind of ancient monitor here. Judging by the connector and its wiring, this is cga. And you need to connect it to the Speccy. From what was on the forum I everything looked. But there’s something I still don’t understand: There are hsync and vsync. As I understand it (and I am somewhat far from electronics) this is horizontal sync pulse and personnel pulse, respectively. These signals have an active low level or high, i.e. are they inverted or not? What is the duration of these pulses? Next. If these monitors (cga/ega) are oriented at 60 Hz, and the spec outputs 50 - then what does this mean? As I understand it, the image will not take up all available vertical area of the screen, right? Will everything be ok horizontally? Why then is it recommended to replace the quartz with a slightly larger one, since 60 Hz is from 50 differ by > 15%, therefore the quartz must be clearly greater than 16 MHz (with basic 14 - you need 16.8). Is this to avoid overclocking the spec too much?

Hello, maximk max> These signals are active low or high Tall. Details at http://nemesis.lonestar.org/reference/video/cga.html max> As I understand it, the image will not occupy the entire available area max> screen vertically, right? Rather, on the contrary, it will stretch vertically. You just have to most likely Tweak the frame scan to catch the synchronization. I don't have a CGA, but Apple and AMIGA monitors work fine at 50 Hz. max> Why then is it recommended to replace quartz with a slightly larger one I THINK that you can play with quartz. Too fast - memory may be running low unstable. But the more, the more pleasing to the eye. Still, 50 Hz is very noticeable flickers.

Hello alexfreed Thank you. And then another question. I found the necessary signals in the circuit, but what’s the best way: turn them on directly from the circuit to the monitor or is it better to put some additional buffer? (which one is better?)

Hello, breeze bre> what kind of Spectrum do you have???? profi, board version 3.2 bre> I personally connected the EGA (AOC) motnitor without any problems! no alterations bre> etc bre> the only thing that had to be taken separately from the VSync and HSync spec board bre> :mad: Yes, I understand, I just don’t want to burn anything :)

Hello, maximk max> run them directly from the circuit onto the monitor or is it better to install max> any additional buffer? (which is better?) What kind of Spectrum do you have???? I personally connected the EGA (AOC) motnitor without any problems! no modifications, etc. the only thing I had to take separately from the VSync and HSync spec board: mad:

Hello, maximk max> Yes, I understand, I just don’t want to burn anything :) Well, what's the matter! check the pinout of the connectors! The main thing is not to destroy the land! :mad: