I’m almost done shipping Rheas, and Wizard testing is slowly coming along. In other news – I got notified that shipping to Australia is not possible at this time. Not sure why, I assume it’s COVID-19 related? Kinda forgot about that one but, as colder weather is slowly coming to northern hemisphere, we might all get a rude reminder very soon.
Speaking of colder wheather, I got myself a new space heater – obviously a used one, quite a lot too, but it was cheap. Didn’t need any repairs but I took it apart and cleaned it properly. Replaced one capacitor I found to be a bit tired. The rest didn’t look too bad so I kept them all original.
The hue of the green is off in the photos, in reality it’s not “radioactive green” but a darker shade (as in, more green than green-cyan). Eyes perceive it differently than camera sensor, I didn’t bother trying to rebalance it. Strictly speaking this is a monochrome monitor with TTL inputs for video and intensity signal – so at best you can have 4 brightness levels including black. Obviously a PC Hercules card in graphics mode can only do 2 levels, on or off, you can do “shades” by dithering pixels since the resolution is pretty high – 720×348.
That being said I have ATI Graphics Solution card that can drive a mono (MDA/Hercules) or color (CGA) monitor, and best of all, it can emulate CGA on mono monitor, and MDA on CGA monitor – including CGA composite mode except without making the pixels fuzzy like an NTSC TV would. Haven’t actually looked at the signals with a scope but I suspect they are modulated per pixel to get 8 different brightness levels. This does have some limitations but works in general. Spot the differences in “CGA” screenshots below:
Working on older electronics is fun. These days if something breaks you might as well throw it away, it’s just a bunch of chips barely visible to the naked eye, and potted/glued so can’t even be opened. I guess I’m getting old because, while I sure enjoy my CPUs and GPUs and super-duper HD flat panel displays, I still miss the old days…
GDEMU 