ASCII schematics were very common for a long time because it was about the only truly portable way to represent them and the are extremely (as in EXTREMELY) small in terms of file size, particularly if they are compressed and the simplest run-length encoding can achieve impressive compression because they are mostly space characters.

Today, something like a PNG file drawn in something like Paint is a very close analog -- virtually every OS installation has something that can read and write such pictures. You can also get very small filesizes, as well, but it requires a bit more effort. People blindly post images that are hundreds of kilobytes or even a couple megabytes and, on the rare occasions when I want to modify the image to point something out, I am almost always able to reduce it down to a few dozen kilobytes and sometimes only a handful of kilobytes -- and all with just Paint.

 

Audioguru manages to add corrections to circuits just using Paint. And he is doing very well.

Even a more or less neat hand-drawn circuit, properly scanned could convey enough.

At the times that Sam Goldwasser posted his notes on repairs, ASCII circuits made sense. But nowadays, they are ridiculous. (The same as posting a .doc archive, by the way).

Me, you ask? Corel Draw.

 

ASCII schematics were very common for a long time because it was about the only truly portable way to represent them ...
...
when I want to modify the image to point something out, I am almost always able to reduce it down to a few dozen kilobytes and sometimes only a handful of kilobytes -- and all with just Paint.

Use paint to drawing with black color and white background, and save in Monochrome bitmap as *.bmp, and then convert to *.gif or *.png, it will get a small file size.

 

It displays fine on my browser. As others have said, it is important to get the intercharacter spacing correct. If the maker used a fixed-pitch font and nothing reduced multiple whitespace to a single space, you should be able to render it properly.

In this particular schematic (which I realize you are just using as an example) there is a connection that doesn't make sense -- namely the emitter of the NPN transistor. I'm guessing there is a resistor to ground that is missing.

Believe it or not, that circuit will switch the PMOS transistor. The gate charges through the base-emitter resistor, and discharges through the emitter. There needs to be a diode across the BE resistor, to prevent reverse BE breakdown when the base goes low.

 

Hello,

In the shown thread there are no code tags used and extra spaced are removed.
Using the code tags, the spaces will be kept and the drawings will show correct.
The code tags also use the fixed spaced font.

There even seems to be an editor for the ascii schematics here:
http://www.tech-chat.de/download.html

Bertus