Category Archives: Children & Computing

The Grumpy Cricket (And Other Enormous Creatures)

December 25, 2023Children & ComputingJohn Goerzen

This Christmas, one of my gifts to my kids was a text adventure (interactive fiction) game for them. Now that they’ve enjoyed it, I’m releasing it under the GPL v3.

As interactive fiction, it’s like an e-book, but the reader is also the player, guiding the exploration of the world.

The Grumpy Cricket is designed to be friendly for a first-time player of interactive fiction. There is no way to lose the game or to die. There is an in-game hint system providing context-sensitive hints anytime the reader types HINT. There are splashes of humor throughout that got all three of my kids laughing.

I wrote it in 2023 for my kids, which range in age from 6 to 17. That’s quite a wide range, but they all were enjoying it.

You can download it, get the source, or play it online in a web browser at https://www.complete.org/the-grumpy-cricket/

Two Boys, An Airplane, Plus Hundreds of Old Computers

September 13, 2016Children & Computing, Family, Hardware, TravelJohn Goerzen

“Was there anything you didn’t like about our trip?”

Jacob’s answer: “That we had to leave so soon!”

That’s always a good sign.

When I first heard about the Vintage Computer Festival Midwest, I almost immediately got the notion that I wanted to go. Besides the TRS-80 CoCo II up in my attic, I also have fond memories of an old IBM PC with CGA monitor, a 25MHz 486, an Alpha also in my attic, and a lot of other computers along the way. I didn’t really think my boys would be interested.

But I mentioned it to them, and they just lit up. They remembered the Youtube videos I’d shown them of old line printers and punch card readers, and thought it would be great fun. I thought it could be a great educational experience for them too — and it was.

It also turned into a trip that combined being a proud dad with so many of my other interests. Quite a fun time.

(Jacob modeling his new t-shirt)

Captain Jacob

Chicago being not all that close to Kansas, I planned to fly us there. If you’re flying yourself, solid flight planning is always important. I had already planned out my flight using electronic tools, but I always carry paper maps with me in the cockpit for backup. I got them out and the boys and I planned out the flight the old-fashioned way.

Here’s Oliver using a scale ruler (with markings for miles corresponding to the scale of the map) and Jacob doing calculating for us. We measured the entire route and came to within one mile of the computer’s calculation for each segment — those boys are precise!

We figured out how much fuel we’d use, where we’d make fuel stops, etc.

The day of our flight, we made it as far as Davenport, Iowa when a chance of bad weather en route to Chicago convinced me to land there and drive the rest of the way. The boys saw that as part of the exciting adventure!

Jacob is always interested in maps, and had kept wanting to use my map whenever we flew. So I dug an old Android tablet out of the attic, put Avare on it (which has aviation maps), and let him use that. He was always checking it while flying, sometimes saying this over his headset: “DING. Attention all passengers, this is Captain Jacob speaking. We are now 45 miles from St. Joseph. Our altitude is 6514 feet. Our speed is 115 knots. We will be on the ground shortly. Thank you. DING”

Here he is at the Davenport airport, still busy looking at his maps:

Every little airport we stopped at featured adults smiling at the boys. People enjoyed watching a dad and his kids flying somewhere together.

Oliver kept busy too. He loves to help me on my pre-flight inspections. He will report every little thing to me – a scratch, a fleck of paint missing on a wheel cover, etc. He takes it seriously. Both boys love to help get the plane ready or put it away.

The Computers

Jacob quickly gravitated towards a few interesting things. He sat for about half an hour watching this old Commodore plotter do its thing (click for video):

His other favorite thing was the phones. Several people had brought complete analog PBXs with them. They used them to demonstrate various old phone-related hardware; one had several BBSs running with actual modems, another had old answering machines and home-security devices. Jacob learned a lot about phones, including how to operate a rotary-dial phone, which he’d never used before!

Oliver was drawn more to the old computers. He was fascinated by the IBM PC XT, which I explained was just about like a model I used to get to use sometimes. They learned about floppy disks and how computers store information.

He hadn’t used joysticks much, and found Pong (“this is a soccer game!”) interesting. Somebody has also replaced the guts of a TRS-80 with a Raspberry Pi running a SNES emulator. This had thoroughly confused me for a little while, and excited Oliver.

Jacob enjoyed an old TRS-80, which, through a modern Ethernet interface and a little computation help in AWS, provided an interface to Wikipedia. Jacob figured out the text-mode interface quickly. Here he is reading up on trains.

I had no idea that Commodore made a lot of adding machines and calculators before they got into the home computer business. There was a vast table with that older Commodore hardware, too much to get on a single photo. But some of the adding machines had their covers off, so the boys got to see all the little gears and wheels and learn how an adding machine can do its printing.

And then we get to my favorite: the big iron. Here is a VAX — a working VAX. When you have a computer that huge, it’s easier for the kids to understand just what something is.

When we encountered the table from the Glenside Color Computer Club, featuring the good old CoCo IIs like what I used as a kid (and have up in my attic), I pointed out to the boys that “we have a computer just like this that can do these things” — and they responded “wow!” I think they are eager to try out floppy disks and disk BASIC now.

Some of my favorites were the old Unix systems, which are a direct ancestor to what I’ve been working with for decades now. Here’s AT&T System V release 3 running on its original hardware:

And there were a couple of Sun workstations there, making me nostalgic for my college days. If memory serves, this one is actually running on m68k in the pre-Sparc days:

Returning home

After all the excitement of the weekend, both boys zonked out for awhile on the flight back home. Here’s Jacob, sleeping with his maps still up.

As we were nearly home, we hit a pocket of turbulence, the kind that feels as if the plane is dropping a bit (it’s perfectly normal and safe; you’ve probably felt that on commercial flights too). I was a bit concerned about Oliver; he is known to get motion sick in cars (and even planes sometimes). But what did I hear from Oliver?

“Whee! That was fun! It felt like a roller coaster! Do it again, dad!”

Mud, Airplanes, Arduino, and Fun

June 15, 2016Children & Computing, Family, Hardware, TravelJohn Goerzen

The last few weeks have been pretty hectic in their way, but I’ve also had the chance to take some time off work to spend with family, which has been nice.

Memorial Day: breakfast and mud

For Memorial Day, I decided it would be nice to have a cookout for breakfast rather than for dinner. So we all went out to the fire ring. Jacob and Oliver helped gather kindling for the fire, while Laura chopped up some vegetables. Once we got a good fire going, I cooked some scrambled eggs in a cast iron skillet, mixed with meat and veggies. Mmm, that was tasty.

Then we all just lingered outside. Jacob and Oliver enjoyed playing with the cats, and the swingset, and then…. water. They put the hose over the slide and made a “water slide” (more mud slide maybe).

Then we got out the water balloon fillers they had gotten recently, and they loved filling up water balloons. All in all, we all just enjoyed the outdoors for hours.

Flying to Petit Jean, Arkansas

Somehow, neither Laura nor I have ever really been to Arkansas. We figured it was about time. I had heard wonderful things about Petit Jean State Park from other pilots: it’s rather unique in that it has a small airport right in the park, a feature left over from when Winthrop Rockefeller owned much of the mountain.

And what a beautiful place it was! Dense forests with wonderful hiking trails, dotted with small streams, bubbling springs, and waterfalls all over; a nice lake, and a beautiful lodge to boot. Here was our view down into the valley at breakfast in the lodge one morning:

And here’s a view of one of the trails:

The sunset views were pretty nice, too:

And finally, the plane we flew out in, parked all by itself on the ramp:

It was truly a relaxing, peaceful, re-invigorating place.

Flying to Atchison

Last weekend, Laura and I decided to fly to Atchison, KS. Atchison is one of the oldest cities in Kansas, and has quite a bit of history to show off. It was fun landing at the Amelia Earhart Memorial Airport in a little Cessna, and then going to three museums and finding lunch too.

Of course, there is the Amelia Earhart Birthplace Museum, which is a beautifully-maintained old house along the banks of the Missouri River.

I was amused to find this hanging in the county historical society museum:

One fascinating find is a Regina Music Box, popular in the late 1800s and early 1900s. It operates under the same principles as those that you might see that are cylindrical. But I am particular impressed with the effort that would go into developing these discs in the pre-computer era, as of course the holes at the outer edge of the disc move faster than the inner ones. It would certainly take a lot of careful calculation to produce one of these. I found this one in the Cray House Museum:

An Arduino Project with Jacob

One day, Jacob and I got going with an Arduino project. He wanted flashing blue lights for his “police station”, so we disassembled our previous Arduino project, put a few things on the breadboard, I wrote some code, and there we go. Then he noticed an LCD in my Arduino kit. I hadn’t ever gotten around to using it yet, and of course he wanted it immediately. So I looked up how to connect it, found an API reference, and dusted off my C skills (that was fun!) to program a scrolling message on it. Here is Jacob showing it off:

Bach, Dot Matrix Printers, and Dinner

January 27, 2016Children & Computing, Family, HardwareJohn Goerzen

Dinner last night started out all normal. Then Jacob and Oliver started asking me about printers. First they wanted to know how an ink jet printer works. Then they wanted to know how a laser printer works. Then they wanted to know what would happen if you’d put ink in a laser printer or toner in an ink jet. They were fascinated as I described the various kinds of clogging and ruining that would inevitably occur.

Then these words: “What other kinds of printers are there?”

So our dinner conversation started to resolve around printers. I talked about daisy wheel printers, line printers, dot matrix printers. I explained the type chain of line printers, the pins of dot matrix. “More printers!” I had to dig deeper into my memory: wax transfer printers, thermal printers, dye sublimation, always describing a bit about how each one worked — except for dye sublimation, which I couldn’t remember many details about. “More printers!” So we went onwards towards the printing press, offset printing, screen printing, mimeograph, and photocopiers. Although I could give them plenty of details about most of the printers, I also failed under their barrage of questions about offset printing. So I finally capitulated, and said “should I go get my phone and look it up while you finish eating?” “YEAH!”

So I looked up the misty details of dye sublimation and offset printing and described how they worked. That seemed to satisfy them. Then they asked me what my favorite kind of printer was. I said “dot matrix, because it makes the best sound.” That had their attention. They stopped eating to ask the vitally important question: “Dad, what sound does it make?” At this point, I did my best dot matrix impression at the dinner table, to much laughter and delight.

Before long, they wanted to see videos of dot matrix printers. They were fascinated by them. And then I found this gem of a dot matrix printer playing a famous Bach tune, which fascinated me also:

I guess it must have all sunk in, because this morning before school Jacob all of a sudden begged to see the fuser in my laser printer. So we turned it around, opened up the back panel — to his obvious excitement — and then I pointed to the fuser, with its “hot” label. I even heard a breathy “wow” from him.

My boys love 1986 computing

November 23, 2014Children & ComputingJohn Goerzen

Yesterday, Jacob (age 8) asked to help me put together a 30-year-old computer from parts in my basement. Meanwhile, Oliver (age 5) asked Laura to help him learn cursive. Somehow, this doesn’t seem odd for a Saturday at our place.

Let me tell you how this came about.

I’ve had a project going on for a while now to load data from old floppies. It’s been fun, and had a surprise twist the other day: my parents gave me an old TRS-80 Color Computer II (aka “CoCo 2”). It was, in fact, my first computer, one they got for me when I was in Kindergarten. It is nearly 30 years old.

I have been musing lately about the great disservice Apple did the world by making computers easy to learn — namely the fact that few people ever bother to learn about them. Who bothers to learn about them when, on the iPhone for instance, the case is sealed shut, the lifespan is 1 or 2 years for many purchasers, and the platform is closed in lots of ways?

I had forgotten how finicky computers used to be. But after some days struggling with IDE incompatibilities, booting issues, etc., when I actually managed to get data off a machine that had last booted in 1999, I had quite the sense of accomplishment, which I rarely have lately. I did something that was hard to do in a world where most of the interfaces don’t work with equipment that old (even if nominally they are supposed to.)

The CoCo is one of those computers normally used with a floppy drive or cassette recorder to store programs. You type DIR, and you feel the clack of the drive heads through the desk. You type CLOAD and you hear the relay click closed to turn on the tape motor. You wiggle cables around until they make contact just right. You power-cycle for the times when the reset button doesn’t quite do the job. The details of how it works aren’t abstracted away by innumerable layers of controllers, interfaces, operating system modules, etc. It’s all right there, literally vibrating your desk.

So I thought this could be a great opportunity for Jacob to learn a few more computing concepts, such as the difference between mass storage and RAM, plus a great way to encourage him to practice critical thinking. So we trekked down to the basement and came up with handfulls of parts. We brought up the computer, some joysticks, all sorts of tangled cables. We needed adapters, an old TV. Jacob helped me hook everything up, and then the moment of truth: success! A green BASIC screen!

I added more parts, but struck out when I tried to connect the floppy drive. The thing just wouldn’t start up right whenever the floppy controller cartridge was installed. I cleaned the cartridge. I took it apart, scrubbed the contacts, even did a re-seat of the chips. No dice.

So I fired up my CoCo emulator (xroar), and virtually “saved” some programs to cassette (a .wav file). I then burned those .wav files to an audio CD, brought up an old CD player from the basement, connected the “cassette in” plug to the CD player’s headphone jack, and presto — instant programs. (Well, almost. It takes a couple of minutes to load a program from audio codes.)

The picture above is Oliver cackling at one of the very simplest BASIC programs there is: “number find.” The computer picks a random number between 1 and 2000, and asks the user to guess it, giving a “too low” or “too high” clue with each incorrect guess. Oliver delighted in giving invalid input (way too high numbers, or things that weren’t numbers at all) and cackled at the sarcastic error messages built into the program. During Jacob’s turn, he got very serious about it, and is probably going to be learning about how to calculate halfway points before too long.

But imagine my pride when this morning, Jacob found the new CD I had made last night (correcting a couple recordings), found my one-line instruction on just part of how to load a program, and correctly figured out by himself all the steps to do in order (type CLOAD on the CoCo, advance the CD to the proper track, press play on the player, wait for it to load on the CoCo, then type RUN).

I ordered a replacement floppy controller off eBay tonight, and paid $5 for a coax adapter that should fix some video quality issues. I rescued some 5.25″ floppies from my trash can from another project, so they should have plenty of tools for exploration.

It is so much easier for them to learn how a disk drive works, and even what the heck a track is, when you can look at a floppy drive with the cover off and see the heads move. There are other things we can do with more modern equipment — Jacob has shown a lot of interest in Arduino projects — but I have so far drawn a blank on ways to really let kids discover how a modern PC (let alone a modern phone or tablet) works.

Update Nov. 24: Every so often, the world surprises me by deciding to, well, read one of my random blog posts. For the benefit of those of you that don’t already know my boys, you might want to know that among their common play activites are turning trees into pretend trains, typing at a manual typewriter, reading, writing their own books, using a cassette recorder, building a PC and learning to use bash or xmonad, making long paper tapes with an adding machine, playing records on a record player, building electric gizmos, and even making mud balls.

I am often asked about the role of the computer in the lives, given that my hobby and profession involves computers. The answer: less than that of most of their peers. I look for opportunities for them to learn by doing, discovering, playing, or imagining. I make no presumption that they will develop the passion for computers that I did. What I want is for them to have the curiosity and drive to learn everything there is to know about whatever they do develop a passion for, so they will be great at it.

Kindergarten Computer Class and Password Security

August 29, 2012Children & ComputingJohn Goerzen

Jacob started Kindergarten last week. More on that in another post.

He’s been loving it, until yesterday. At least part of his disgruntlement was because it was his first visit to computer class. Putting together a few conversations, we learned this:

Jacob: Something was different about Kindergarten today.

Us: Oh? What was it?

Jacob: I had computer class today.

Us: What did you do?

Jacob, super frustrated: Nothing. NOTHING, NOTHING, NOOOO THIIING. Nothing.

Us: You didn’t get to use a computer?

Jacob: All we did was log on and log off the whole time. Log on and log off. My username is Jacob and my password is Jacob. (annoyed and confused voice) Why are they the same??

I guess his teachers weren’t used to children that had been logging on to computers for two years before Kindergarten. And probably also weren’t expecting any of them to take some sort of offense at their password poicy. He probably couldn’t appreciate how reasonable it was to tech Kindergarteners how to log in to a computer on the first day of computer class…

I introduced my 5-year-old and 2-year-old to startx and xmonad. They’re DELIGHTED!

June 20, 2012Children & Computing, FamilyJohn Goerzen

Two years ago, Jacob (then 3) and I built his first computer together. I installed Debian on it, but never put a GUI on the thing. It’s command-line, and has provided lots of enjoyment off and on over the last couple of years. I’ve written extensively about what our boys like to do, and the delight they have at learning things on the command line.

The looks of shock I get from people when I explain, as if it’s perfectly natural, that my child has been able to log in by himself to a Linux shell since age 3, are amusing and astounding. Especially considering that it is really not that hard. Instead of learning how to run an Xbox, he’s learned how to run bash. I like that.

Lately, Jacob (now 5) hasn’t been spending much time with it. He isn’t really at a stage where he wants to push his limits too far, I think, but yet also gets bored with the familiar. So I thought it was time to introduce a GUI in a limited fashion, perhaps to let him download photos and video from his Vtech toy camera (that takes real low-res photos and videos which can be downloaded over a USB1 link). He’s familiar with the concept, at least somewhat, having seen GUIs on Terah’s computer (Gnome 2) and mine (xfce4 + xmonad).

So last night, Oliver (age 2) and I went down to the basement on a mouse-finding expedition. Sure enough, I had an old PS/2 mouse down there that would work fine. The boys both helped string it through the desk up on our play room, and were tremendously excited to see the red light underneath it when the computer came on. Barely able to contain the excitement, really. A bit like I remember being when I got my first mouse (at a bit of an older age, I suppose.)

I helped him them in as root for the very first time. (Jacob typed “root”, and I typed the password, and provided the explanation for why we were telling the computer we were “root”.) Jacob and Oliver alternated typing bits of some apt-get command lines. Then while we waited for software to download, I had to answer repeated questions of “how soon will the mouse work?” and “what does ‘install’ mean?”

Finally it was there, and I told Jacob to type startx. I intentionally did not install a display manager; more on that later. He pressed Enter, the screen went blank for about 5 seconds, and then X appeared. “Excited” can’t begin to describe how they acted. They took turns playing with the mouse. They loved how the trash can icon (I started with XFCE) showed trash IN the trash can.

But they are just learning the mouse, and there’s a lot about a typical GUI that is unfriendly to someone that isn’t yet proficient with a mouse. The close buttons are disappointingly small, things can be too easily dragged on and off the panel and menus. When I sat down to think about it, the typical GUI design does not present a very good “it always works the same” interface that would be good for a child.

And then it occurred to me: the perfect GUI for a child would be simply xmonad (a tiling window manager that can be controlled almost entirely by keyboard and has no need for mouse movements in most cases.) No desktop environment, no file manager in the root window. Just a window manager in the classic X way. Of course!

So after the boys were in bed, I installed xmonad. I gave Jacob’s account a simple .xsession that starts a terminal and xmonad.

Today, Jacob informed me that he wanted his computer to look “just like yours.” Playing right into my hands, that was! But when he excitedly typed startx, he said it wasn’t just like mine. Uh oh. Turns out he wanted the same wallpaper as my computer uses. Whew. We found it, I figured out that xli(1) loads it in the root window, and so I added a third line to .xsession. More delight unlocked!

Jacob mastered the basics of xmonad really quickly. Alt-Shift-C to close a window. Alt-Shift-Q to quit back to the “big black screen”. Alt-Shift-Enter to get a terminal window.

We launched thunar (the XFCE file manager) and plugged in his camera. He had a good deal of fun looking at photos and videos from it. But then I dropped the true highlight of the day for him: I offered to install Tuxpaint for him. That’s probably his favorite program of all time.

He watched impatiently as apt-get counted down 1m30s for tuxpaint and its libraries. Then we launched it, and he wanted to skip supper so he could keep playing Tuxpaint on “my VERY OWN COMPUTER!”

I’d been debating how to introduce GUIs for a very long time. It has not escaped my attention that children that used Commodores or TRS-80s or DOS knew a lot more about how their computers worked, on average, than those of the same age that use Windows or MacOS. I didn’t want our boys to skip an entire phase of learning how their technology works. I am pleased with this solution; they still run commands to launch things, yet get to play with more than text-based programs.

At bedtime, Jacob asked me, very seriously:

“Dad, how do I start tuxpaint again?”

“First you log in and type startx. Then you can use the mouse.”

Jacob nods, a contemplative look on his face..

“Then,” I continue, “you type tuxpaint in the terminal, and it comes right up.”

Jacob nodded very seriously a second time, as if committing this very important information to long-term memory. Then gave a single excited clap, yelled “Great!”, and dashed off.

XMPP for Children

February 11, 2012Children & Computing, FamilyJohn Goerzen

When Jacob was just born, I wondered how I might introduce them to computing. I thought over various things, but that wasn’t really the most pressing thing right then.

I don’t suppose that I could have predicted installing an XMPP IM server (Prosody) for the boys. And I certainly couldn’t have predicted creating accounts named: jacob, oliver, butterfly, bear. Because, as Jacob pointed out to me, if (Jacob’s favorite toy) butterfly is typing with his wings, then he shouldn’t be logged in as Jacob. I admire my 5-year-old’s security consciousness…

Anyhow, as I mentioned yesterday, Jacob and Oliver enjoy “their” computer, which I recently put on the LAN. The firewall does not pass any of its traffic to the Internet, though, with very limited exceptions.

Jacob can read, and is starting to enjoy typing as well. So I thought he would enjoy sending IMs to me. As his computer has no GUI, I needed a text-mode client. Something with an IRC-like interface that could be scripted to open up a window with me directly sounded perfect. Initially I tried irssi’s XMPP plugin, but it proved to be too buggy (wanting to always latch on to a particular resource on the remote end, not having very predictable window behavior, etc.) So I switched to mcabber. With a couple of quick configuration bits to get him automatically logged in, remove superflous windows, and connect him directly to a chat with me, it was set. And well-loved. He sent me a mix of real words and random things he created by replacing letters in “Jacob” or by holding down keys.

In the mcabberrc, besides the obvious setting of username and password, there is:

set log_win_height = 1 set hook-post-connect = source ~/.mcabber/post-connect.rc

The hook is simply:

roster search Dad roster hide

After awhile, Jacob wanted to switch computers. He wanted to use my laptop, and me use his computer. He refused to switch back. I asked him why. “Because on your computer, my name is red.” I should have known. I set it to bright white on his computer, but I think tomorrow we may need to upgrade him to the color monitor I’ve been saving for just such an occasion… It will be a whole new set of discoveries, I’m sure.

Update: I also tried out freetalk, which looked like it would meet my goals nicely. The problem was it didn’t have a dedicated “everything typed goes to this person” mode. It did have a mode where it put the person’s JID on the command line by default, but excessive use of backspace key by a 5-year-old could wipe that out and leave it in a state where he’d be confused.

Shell Scripts For Preschoolers

February 10, 2012Children & Computing, Debian, Family, ProgrammingJohn Goerzen

It probably comes as no surprise to anybody that Jacob has had a computer since he was 3. Jacob and I built it from spare parts, together.

It may come as something of a surprise that it has no graphical interface, and Jacob uses the command line and loves it — and did even before he could really read.

A few months ago, I wrote about the fun Jacob had with speakers and a microphone, and posted a copy of the cheat sheet he has with his computer. Lately, Jacob has really enjoyed playing with the speech synthesizer — both trying to make it say real words and nonsense words. Sometimes he does that for an hour.

I was asked for a copy of the scripts I wrote. They are really simple. I gave them names that would be easy for a preschooler to remember and spell, even if they conflicted with existing Unix/Linux commands. I put them in /usr/local/bin, which occurs first on the PATH, so it doesn’t matter if they conflict.

First, for speech systhesis, /usr/local/bin/talk:

#!/bin/bash echo "Press Ctrl-C to stop." espeak -v en-us -s 150

espeak comes from the espeak package. It seemed to give the most consistenly useful response.

Now, on to the sound-related programs. Here’s /usr/local/bin/ssl, the “sound steam locomotive”. It starts playing a train sound if one isn’t already playing:

#!/bin/bash pgrep mpg321 > /dev/null || mpg321 -q /usr/local/trainsounds/main.mp3 & sl "$@"

And then there’s /usr/local/bin/record:

#!/bin/bash cd $HOME/recordings echo "Now recording. Press Ctrl-C to stop." DATE=`date +%Y-%m-%dT%H-%M-%S` FILENAME="$DATE-$$.wav" chmod a-w *.wav exec arecord -c 1 -f S16_LE -c 1 -r 44100 "$FILENAME"

This simply records in a timestamped file. Then, its companion, /usr/local/bin/play. Sorry about the indentation; for whatever reason, it is being destroyed by the blog, but you get the idea.

#!/bin/bash case "$1" in train) mpg321 /usr/local/trainsounds/main.mp3 ;; song) /usr/bin/play /usr/local/trainsounds/traindreams.flac ;; *) cd $HOME/recordings exec aplay `ls -tr| tail -n 1` ;; esac

So, Jacob can run just “play”, which will play back his most recent recording. As something of a bonus, the history of recordings is saved for us to listen to later. If he types “play train”, there is the sound of a train passing. And, finally, “play song” plays Always a Train in My Dreams by Steve Gillette (I heard it on the radio once and bought the CD).

Some of these commands kick off sound playing in the background, so here is /usr/local/bin/bequiet:

#!/bin/bash killall mpg321 &> /dev/null killall play &> /dev/null killall aplay &> /dev/null killall cw &> /dev/null

A 4-year-old, Linux command line, and microphone

July 30, 2011Children & Computing, Family, LinuxJohn Goerzen

There are certain times when I’m really glad that we have Linux on the house for our boys to play with. I’ve already written how our 4-year-old Jacob has fun with bash and can chain together commands to draw ASCII animated steam locomotives. Today I thought it might be fun to install cw, a program that can take text on standard input and play it on the console speaker or sound card as Morse code. Just the sort of thing that I could see Jacob eventually getting a kick out of.

But his PC was mute. We opened it up and discovered it didn’t have a console speaker. So we traipsed downstairs, dug out an external speaker, and I figured out how to enable the on-board audio chipset in the BIOS. So now the cw command worked, but also there were a lot of other possibilities. We also brought up a microphone.

While Jacob was busy with other things, I set to work getting things hooked up, volume levels adjusted, and wrote some shell scripts for him. I also printed out this reference sheet for Jacob:

He is good at reading but not so good at spelling. I intentionally didn’t write down what the commands do, hoping that this would provide some avenue for exploration for him. He already is generally familiar with the ones under the quiet category.

I wrote a shell script called “record”. It simply records from the microphone and drops a timestamped WAV file in a holding directory. He can then type “play” to simply play back whatever he recorded most recently. Easy enough.

But what he really wanted was sound for his ASCII steam locomotive. So with the help of a Google search for “steam train mp3”, I wrote a script “ssl” (sound steam locomotive) that starts playing the sound in the background if it isn’t already going, and then runs sl to show the animation. This was a big hit.

I also set it up so he can type “play train” to hear that audio, or “play song” to play our favorite train song (Always a Train in My Dreams by Steve Gillette). Jacob typed that in and sat still for the entire 3 minutes listening to it.

I had to hook up an Ethernet cable to his machine to do all this, and he was very interested that I was hooking his computer up to mine in some way. He thought all the stuff about cables in the walls was quite exciting.

The last thing I did was install flite, a speech synthesis program. I wrote a small shell script called “talk” which reads a line at a time from stdin and invokes flite for each one (to give more instant feedback rather than not starting playback until after having read a large block from stdin). He had some fun hearing it say his name and other favorite words, but predictably the most fun was when he typed gibberish at it, and heard it try to pronounce or spell nonsense words.

In all, he was so excited about this new world of computer sound opened up to him. I’m sure there will be lots of happy experimentation and discovery going on.

Update Feb 10, 2012: I have posted the shell scripts behind this.

The Changelog

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