Jacob is very interested in how things work. He’s 3.5 years old, and into everything. He loves to look at propane tanks, as the pressure meter, and open the lids on top to see the vent underneath. Last night, I showed him our electric meter and the spinning disc inside it.

And, more importantly, last night I introduced him to the Linux command line interface, which I called the “black screen.” Now, Jacob can’t read yet, though he does know his letters. He had a lot of fun sort of exploring the system.

I ran “cat”, which will simply let him bash on the keyboard, and whenever he presses Enter, will echo what he typed back at him. I taught him how to hold Shift and press a number key to get a fun symbol. His favorite is the “hat” above the 6.

Then I ran tr a-z A-Z for him, and he got to watch the computer convert every lowercase letter into an uppercase letter.

Despite the fact that Jacob enjoys watching Youtube videos of trains and even a bit of Railroad Tycoon 3 with me, this was some pure exploration that he loves. Sometimes he’d say, “Dad, what will this key do?” Sometimes I didn’t know; some media keys did nothing, and some other keys caused weird things to appear. My keyboard has back and forward buttons designed to use with a web browser. He almost squealed with delight when he pressed the forward button and noticed it printed lots of ^@^@^@ characters on the screen when he held it down. “DAD! It makes LOTS of little hats! And what is that other thing?” (The at-sign).

I’ve decided it’s time to build a computer for Jacob. I have an old Sempron motherboard lying around, and an old 9″ black-and-white VGA CRT that’s pretty much indestructible, plus an old case or two. So it will cost nothing. This evening, Jacob will help me find the parts, and then he can help me assemble them all. (This should be interesting.)

Then I’ll install Debian while he sleeps, and by tomorrow he should be able to run cat all by himself. I think that, within a few days, he can probably remember how to log himself in and fire up a program or two without help.

I’m looking for suggestions for text-mode games appropriate to a 3-year-old. So far, I’ve found worm from bsdgames that looks good. It doesn’t require him to have quick reflexes or to read anything, and I think he’ll pick up using the arrow keys to move it just fine. I think that tetris is probably still a bit much, but maybe after he’s had enough of worm he would enjoy trying it.

I was asked on Twitter why I’ll be using the command line for him. There are a few reasons. One is that it will actually be usable on the 9″ screen, but another one is that it will expose the computer at a different level than a GUI would. He will inevitably learn about GUIs, but learning about a CLI isn’t inevitable. He won’t have to master coordination with a mouse right away, and there’s pretty much no way he can screw it up. (No, I won’t be giving him root yet!) Finally, it’s new and different to him, so he’s interested in it right now.

My first computer was a TRS-80 Color Computer (CoCo) II. Its primary interface, a BASIC interpreter, I guess counts as a command-line interface. I remember learning how to use that, and later DOS on a PC. Some of the games and software back then had no documentation and crashed often. Part of the fun, the challenge, and sometimes the frustration, was figuring out just what a program was supposed to do and how to use it. It will be fun to see what Jacob figures out.