The Membership Card Manifesto
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[note: This text was extracted edited from Lee Hart's posts, with slight editing for
continuity, by Herb Johnson. Last updated Apr 6 2006]

<a name="preamble">Preamble
---------

The BASIC Stamps are very popular, and widely promoted as cheap and easy
and simple to use. And they are... if you are already a reasonably good
engineer or technician, over-$100 for a starter kit doesn't bother you,
and you have and are skilled at using a PC.

What if you *aren't* at this level? Your alternatives are 100s of under-$20
dumbed-down electronics kits for building LED blinkies, noisemakers,
crude radios, primitive robots, etc. They are completely stand-alone,
and don't have computers (or when they do, it's as a secret "black box"
chip to do some preprogrammed function). However, you quickly get bored
with the limited scope (101 ways to blink an LED), and the opportunities
for expansion are limited. The construction techniques they use are
toy-like, and don't teach you much about building real circuits.

But, I can't find any inexpensive stand-alone "starter" electronics kits
that teach you about computers, programming, or building things with
real parts. I'm looking for them for my son, who is 9. 

Also, I teach courses for 4th-6th grade students to build electric cars (see
www.bestoutreach.org). Most kids come in with essentially ZERO
tool-using skills; they have never used a hammer, saw, or screwdriver.
They have never built anything "real"; just played with Legos or virtual
stuff on a computer. You would not believe how excited the kids get.
They are DESPERATE to play with something real! Use real tools to build
real things, that really work! While seeing something on a 19" LCD is more
impressive than a blinking LED, seeing it in the form of a robot running
around is even more impressive.

So, what I'm imagining is a computer like the classic BASIC Stamp on a solderless
breadboard, with a book and bag of parts. However, it won't depend on a PC 
to provide all its access and programming. Give it a front panel so you can start
right in at the most basic level. The lessons would be ways to expand it. Add a
keypad and 7-segment display. Add mass storage. Add a video display. Link it to a 
PC. Connect switches and lights and motors. Build a robot!

In the process, they'll learn how digital logic and computers work. Write
low-level programs, save them in ROM, and use them as subroutines in
bigger programs. Go from machine language to hex to assembler to BASIC
and beyond! 

But I've been trying to teach my 9-year-old son Tiny BASIC.
It is hard for adults to realize is that kids think very differently
from adults. Their logical abilities are almost
non-existent, and they solve problems by trial-and-error. They
cannot solve problems that involve more than a very few steps
except by rote memorization. So, languages like Forth or C are out. 
They are just plain too complex
for young children. Their very power and richness become a curse.

The keyboard and screen are also a curse. Almost all computer languages
require you to read and type well; a problem for kids. Kids also have
problems with the extremely rigid syntax and grammar of computer
languages. So kids today don't program because they don't have any 
computers that make it fun and easy to learn how.

Logo was designed to address all these problems. In its most basic
form, you have keys for basic functions of movement, and keys which 
can be assigned whatever functions a kid will come up with. 

So, my thought is to put a couple stepper motors and wheels on the
computer card, program it with an 1802-based Logo, and let the kids have at it!
Draw their name, teach it to run a maze, or sumo-wrestle. And in the
process, begin learning the wonderful world of math, logic and
programming.

<a name="proposition">Proposition
-----------

My goals for the Membership card are:

  - a fully functional Elf computer
  - as inexpensive as possible
  - as simple as possible in design and in use
  - as easy to build as possible
  - suitable for a 9-year-old, interesting to anyone
  - low power but adequate speed
  - simple expansions for more elaborate use with robots or computers
  - but immediately usable without any other computer or device

Of course it is limited. Everyone wants a more powerful, more elaborate
system. But, I know only too well how my own "powerful, elaborate"
projects go. I can happily dream about them forever; but they never get
built or finished! This is one you can build in an afternoon. 

I'm out to encourage my 9-year-old son. I want a computer that is
so simple that he will stick-to-it long enough to actually get
it built and working.

I hope to have a kit with all the parts and PC board offered at a low
price. I'm designing around parts I already have, and will sell cheap
(like the 5101 RAMs). For instance, the LEDs I'm using are 2 cents each,
and the toggle switches are 13 cents each if we buy enough for 25
boards.

With this "membership card", you can have a working Elf the same day you
start. No need to wirewrap it from scratch, or assemble a kit with
several times more parts. The key is [that] the beginner needs to see
results quickly. If it takes too long, he'll either never start, or never finish.

As the original Elf demonstrated, I don't think you will soon exhaust the possibilities of
even so basic a computer. But when you do, there are ways to expand it, or
you can transfer to another 1802-class computer. This design can plug its Input port
into a PC's parallel port, to download once the toggle switches get
old (which won't take long!) or when your work is longer or more complex.
The small 5101 RAMs can be replaced with a 62256 RAM so there is enough
memory to run Tiny BASIC and other "real" programs.

I also intend to have a robot for which the "membership" card is its
brain. Something like the Logo Turtle robot, that has a left and right
motor that you can drive forward/reverse to make it move, turn, feel
objects with bump switches, push them around, run mazes, etc.

Einstein said, "Things should be kept as simple as possible -- but not
too simple." This card, like the Elf computers, illustrates this philosophy.
They are complicated enough to do the job and be "interesting", yet simple enough
to fully understand and explore.