I'm getting one of these http://www.old-computers.com/museum/computer.asp?st=1&c=446
I'm planning to build a server inside it. And I was thinking of using the built in CGA-monitor as a statusdisplay (LCDInfo style, or whatever the cool geeks use nowadays).
The screen is monochrome amber so it would probably look a bit like the Planar EL-screens some have been using in their mods. And I want to use an Arduino (or something like it) as a middleware solution… PC -> Arduino -> Screen
I have been checking up a bit, and CGA is a RGBI signal using TTL-communications. 4 lines (RGB + Intensity), combined with HSYNC (15.75KHz) and VSYNC (60Hz).
The 4 "color-inputs" are logic on or off. The combination of these generates up to 16 colors. However, as this is an amber screen, it would probably be easiest to start with "all-high" or "all-low"… White and Black.
So the problem is the following… I could probably both wire and code the arduino to flip the TTL-lines on and off, but I'm not sure what I do with the HSYNC and VSYNC inputs. And how to time the TTL-flips to correspond to pixels on the screen. (The standard CGA resolution is 320×200).
I'm not very good at electronics, but I'm very good at following instructions, and taking hints
Has anyone tried this before?
Could I maybe use a modified version of this? http://www.eosystems.ro/deogen/deogen_en.html
I don't need to use an Arduino. But I want to keep it as simple as possible.
It might seem that the monitor in question actually is a composite monitor, and not a "real" CGA input monitor. So that probably makes things a bit easier. But I'm still interested in how to generate a pure CGA signal using a microcontroller…