Re: Computing Editorial (please read)

[Lee Hart <leeahart@earthlink.net>]

Paul Schlyter wrote:
> Teaching yourself basic programming is of course quite feasible
> on an Apple II...

Today, computers don't come with ANY programming languages.

> I'm not proposing a modern PC as an alternative -- a modern
> microcontroller is a much better alternative: it has all the
> advantages you listed above, with the added advantage that
> it's still manufactured.

This matters if you want to make more. But one's first projects are
always one-of-a-kind models, built just for learning.

>> I don't work much with the Apple II, but here are three examples of
>> projects that I have seen students do. [snip]

> While these projects probably were both entertaining and educationg,
> did any one of them "revolutionzie the future world" in any way?

It's too soon to say. They were built by kids still in school! I cannot
say if any of them will be a future Nikola Tesla or Tom Edison. But it
would please me if I could have provided the right tools for today's
kids to develop the logical thinking and construction skills so they
*could* do something great one day!

> You can pick up an old PC for next to nothing as well... they're
> even more abundant than old Apple II's .....

Yes, quite so. But, what can you do with it? Would a student be likely
to be able to execute any of the example projects I mentioned earlier?
Even as an experienced engineer, I had trouble understanding how the
hardware in the original PC worked.

>> Is there anything the BASIC stamp can do that the Apple II can't?

> Sure!  For instance:
> 1. It's still manufactured

That's a plus, if you happen to need more than one. More likely, you'd
use the Apple II you got for free for learning and testing "model 1".
Then build "model 2" around something more modern.

> 2. You can use it to build a device which can fit in a matchbox.
>    Not the slightest chance of doing that with an Apple II .....

Small is usually the enemy of learning. Big parts, big boards, and big
traces make it easier to work on.

> The Apple II was 6502 based, not Z80 based.  Also, today's Z80
> descendants (which are faster than the old Z80A) are used in embedded
> controllers, not general-purpose microcomputers.

The 6502 is still around, too, in the form of faster more highly
integrated versions, also used in embedded controllers.

However, my point is not that the Apple II was the perfect computer. My
point was that it was one (of many) examples of a generic, open,
easy-to-use computer. Computers like it are what inspired and trained a
whole generation of today's computer engineers. There is nothing like
them today. They've been replaced by appliance computers, that are not
understandable or programmable by the average person.

At the other extreme, there are microcontrollers. They are wonderful
devices, but built for trained professionals, not amateurs. The only way
I see beginners using microcontrollers is when they are prepackaged into
some product, designed and programmed by professionals so the user is
totally isolated from the actual hardware or software (Lego Mindstorms
for example).

>>> When you built your first computer, the Internet was nowhere as
>>> widely accessible as it is today.  That's a big difference.

>> Yes. But does it help, or hinder? If you were a high school student
>> and wanted to build your own computer, where would you go? Where
>> are the plans? The parts? The kits? The software? The information
>> on how to do it?

> This is the contemporary problem of "information explosion"...

Yes. And "explosion" is a good word. There is too much information, with
too little organization. Finding 10 answers to a question is no good
when you can't tell which one is right. There is a natural human
tendency to pick the answer you see the most, or who shouts the loudest,
or who lies the most convincingly.

> perhaps the younger generation are better prepared to deal with it?

I do not see any evidence of this. In fact, there have been studies
where students were asked to answer questions on various topics using
the www. The kids were extremely likely to take the first answer they
found, and accept it uncritically.

> But if you want to build your own computer, why would you require
> software?

There are two reasons. First, if you are doing it as an educational
project, you want examples to look at and learn from. (It is a rare
person who can learn without examples).

Second, if you are doing it to investigate some alternative
architecture, then you'd want whatever software tools are available to
"jump start" your project. (Follow the existing roads as far as you can
before turning off in your own direction).

> You can buy a microcontroller, and hook up a power supply and a few
> external components...

Yes. But then it doesn't do anything at all. And no way to probe pins to
tell if it is working. And there is no way to get a program into it.

So, to get it to actually do anything, you need a PC and a lot of
hardware and software. That's quite a leap up the ladder.

Contrast this with my first microcomputer. It had an 1802 CPU, a 6810
RAM, ten toggle switches, 8 LEDs on an 8-bit latch, and a couple gate
packages. It was wired up on one of those white E&L breadboard sockets.

I learned a vast amount about computer hardware and software from that
little "ELF" computer. I could watch the address, data, and control
lines with my logic probe (an LED and resistor). I could toggle in each
instruction, and watch it execute (the 1802 worked at 0 clock frequency,
so I could single-step its clock with a switch; no scope needed). I can
still vividly recall the "AHA!!!" feeling I goat as I figured out how it
all worked.

>> we have microcomputers today because people DID dream of building
>> their own computer -- and they did it!!!

> Nah -- we have microcomputers today because we have microelectronics.
> Dreams alone don't build computers.

I meant that the microprocessor wasn't designed to be a computer; it was
designed as controller. It was hobbyists who saw it as a way to build a
"real" computer. All the early microcomputers were built by such people.

>>> So why don't you put up a web site which shows these beginners
>>> how very easy this is nowadays?

>> That's a good idea, although the web is not where my skills lie.
>> I have instead been doing a lot of volunteer work in schools,
>> showing kids how to do it. But I am only one person. I'm writing
>> here so perhaps others will do their part, too.

> You don't need to make the web site fancy -- stick with fairly
> simple HTML, and some images here and there where appropriate.
> The important thing is the information, not the appearance.

I have been helping others to do this. See <http://www.cosmacelf.com>.
It covers the old ELF type computers that I started with. I've retyped
in a lot of the old books and manuals, and contributed the software I
wrote.

> perhaps you prefer to teach what you know by word of mouth instead?

It's the kids that prefer to be taught by demonstrations and hands-on
examples. Plain old text on a page (or on a computer screen) just
doesn't get people all that excited. It's extremely hard to get people
away from the book or computer screen, and onto the workbench!
-- 
Lee A. Hart                Ring the bells that still can ring
814 8th Ave. N.            Forget your perfect offering
Sartell, MN 56377 USA      There is a crack in everything
leeahart_at_earthlink.net  That's how the light gets in - Leonard Cohen