beginning microcontrollers and tinkering

I basically have 3 questions.

Are there any groups devoted to homebrewing CPU's and building computers from
microprocessor and chip level?  I've found a few web sites and threads related
to FPGA CPU and building from 7400 level circuitry, but haven't found a web
forum or Usenet group yet.  I have no desire to build a complete computer, just
interested in the basic design and its application to my projects.

Are there any kits left similar to the AES ones where you program on a hex
keypad in assembly?  I've found some vendors but the kits are either high
priced or meant for wholesale to educators.  I've seen a few dated kits on
Ebay, unfortunately at high prices due to collectors.  Is there a present day
analog to these kits?  I have some fond memories of "coding" on
microcontrollers as a kid, and would like to try it again.  I realize this has
little practical value, this is just for fun.

Any suggestions for a cheap (e.g. $50 to $150) simulator or development kit for
learning the basics?  I thinking Basic Stamp might be a start.  I'd like to
avoid c, and use basic, forth, or some such.  I'm not sure why I'm biased
against c but I am, and another language would be preferred.

Michael

Michael, I am afraid those keypad kits are a thing of the past. But you can get
very low cost evaluation kits. The Texas MSP430 starts at about $50 for the kit,
plus compiler, program cable and the whole enchilada. Then when you want to build
some real stuff you can buy very low cost breadboards at lots of places, I think
the cheapest one with just a processor, crystal and programming connector are
around $10.

Programming is easier than in the old days. You can download the stuff from the PC
into flash memory. It'll keep it's brains even when you remove power, unlike those
keypad scheme of the olden days.

Regards, Joerg.

In comp.arch.embedded, jealousxmp@aol.commonplace (jealous xmp) wrote:

>I basically have 3 questions.
>
>Are there any groups devoted to homebrewing CPU's and building computers from
>microprocessor and chip level?  I've found a few web sites and threads related
>to FPGA CPU and building from 7400 level circuitry, but haven't found a web
>forum or Usenet group yet.  I have no desire to build a complete computer, 

   This is a little confusing - yes, it's possible to create a
microprocessor or microcontroller out of an FPGA or a LOT of discrere
7400-style logic gates, but I don't think that's what you want to do.
You apparently want an off-the-shelf microcontroller to write programs
for.

>just
>interested in the basic design and its application to my projects.
>
>Are there any kits left similar to the AES ones 

   What's AES? I only know of Audio Engineering Society, and that's
obviously not it from the context.

>where you program on a hex
>keypad in assembly?  

   you mean like the KIM-1? Here's one just like the one I own:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1247&item=4123232803
My roomate in college had the earlier model from before Commodore
bought MOS Technology - the only difference was it said "MOS
Technology" instead of having the Commodore name by the crystal.
   And technically, entering the codes in with the hex keypad is
entering machine code, not assembly. Assembly for the KIM-1 was done
'by hand' on the sheet(s) of paper I wrote the program on. It didn't
take a lot of doing that to start to remember 6502 opcodes, and I
could enter short programs in hex (to do things like increment the
display location, call the ROM display routine, then loop) without
writing them in assembly. EA is NOP, 4C is absolute long jump (low
byte first), A9 is LDA immediate... interesting how much I can
remember. I'd gladly trade it for some more modern stuff to put on my
resume...

>I've found some vendors but the kits are either high
>priced or meant for wholesale to educators.  I've seen a few dated kits on
>Ebay, unfortunately at high prices due to collectors.  Is there a present day
>analog to these kits?  

   Few people had Proccesor Technology Sol's or similar with
cross-assemblers for their favorite microprocessor back then (such
systems had assemblers only for the processor they used anyway) ...the
reason for the keypad on the eval boards was so that the system was
completely self-contained, and you had SOME way of entering your code.
   Nowadays everyone has a windows PC, and chip makers give away
assemblers and (usually code-size-limited) C compilers for their
microcontrollers. Code transfer, control and debugging are all done
through a serial port connection between the evaluation board and the
PC, so now the only button needed on the board is reset.

>I have some fond memories of "coding" on
>microcontrollers as a kid, and would like to try it again.  I realize this has
>little practical value, this is just for fun.
>
>Any suggestions for a cheap (e.g. $50 to $150) simulator or development kit for
>learning the basics?  I thinking Basic Stamp might be a start.  I'd like to
>avoid c, and use basic, forth, or some such.  I'm not sure why I'm biased
>against c but I am, and another language would be preferred.

   If you really want to use a keypad to enter code, you might find
the 'best' language is assembly, assemble on the PC, then you can put
in the hex code 'by hand'. As you write larger programs, you'll
eventually want to use a serial port connection as modern eval boards
use.

>Michael

-----
http://mindspring.com/~benbradley

Besides the reasons Ben gave there are others why a PC download to the uC is making
more sense today. Many uCs need to receive a lot of configuration data before they
can do anything. A lot more than the old ones. Secondary clocks need to be set,
multi-use ports need to be dedicated, internal hardware functions must be routed
and so on. That would be a real hassle to pound into a keypad every single time you
want to change some code.

Regards, Joerg.

"jealous xmp" <jealousxmp@aol.commonplace> wrote in message
news:20040409182117.11269.00000106@mb-m15.aol.com...
> I basically have 3 questions.

Ok, shoot.

> Are there any groups devoted to homebrewing CPU's and building
computers from
> microprocessor and chip level?  I've found a few web sites and threads
related
> to FPGA CPU and building from 7400 level circuitry, but haven't found
a web
> forum or Usenet group yet.  I have no desire to build a complete
computer, just
> interested in the basic design and its application to my projects.

Sounds like you might possibly be interested in PICs, AVRs, or maybe the
TI MSP430 instead.  However, on the unusual chance that you're really
interested in FPGA implementations of older micro technollogy (RCA 1802
for example) then look at www.cosmacelf.com  I believe that one of the
"cult" members has implemented an FPGA core that fully emulates an 1802.
For some odd reason there is quite a following for this very early
architecture.

Don't tell anyone, but I still have the original ELF II that I built in
the late 70's.  It's a bit fancier than the original ELF concept having
the deluxe HEX keypad instead of 8 toggle switches for entering your
hand assembled code.  Experienced coders keyed in a memorized routine
that sequenced memory (filled ram with sequential numbers representing
the 8-bit address of the location).  That way when they were keying in a
long piece of code they could check and make sure that an unsuppressed
key-bounce on the Input button wasn't about to ruin their day.   ;-)

> Are there any kits left similar to the AES ones where you program on a
hex
> keypad in assembly?  I've found some vendors but the kits are either
high
> priced or meant for wholesale to educators.  I've seen a few dated
kits on
> Ebay, unfortunately at high prices due to collectors.  Is there a
present day
> analog to these kits?  I have some fond memories of "coding" on
> microcontrollers as a kid, and would like to try it again.  I realize
this has
> little practical value, this is just for fun.

Oh you might be surprised just how practical (and cheap) modern
microcontrollers are.  Devices like PICs and AVRs are really handy at
gluing things together in the real world.  You'll start seeing
applications for them every where you look.

> Any suggestions for a cheap (e.g. $50 to $150) simulator or
development kit for
> learning the basics?  I thinking Basic Stamp might be a start.  I'd
like to
> avoid c, and use basic, forth, or some such.  I'm not sure why I'm
biased
> against c but I am, and another language would be preferred.

You didn't rule out assembly language, good.  I highly suggest you start
your trip down the road of micro programming by using assembler at
first.  IMO you gain a far better understanding of what's really going
on.  I have used only assembler for all my PIC projects, but I have also
used C for some 8052 stuff.

The stamp is ok, but a bit slow for some things.  If you're comfortable
with soldering, you can really do allot more with PIC (or AVR) chips.
I've gotten a bunch of projects working on solderless breadboards and
then made them more permanent by transferring them to a pre-fab circuit
board.  It's certainly allot more affordable than dedicating stamp
modules to my projects.  ;-)

>A9 is LDA immediate... interesting how much I can
>remember. I'd gladly trade it for some more modern stuff to put on my
>resume...

I hear you on that score. My head is filled with 8080 opcodes. I built a
Polymorphics Poly-88 from a kit, though other people had to correct some
mistakes I made in building it for it to work properly. I remember sitting on
the floor of my dorm room keying in programs from Dr.Dobbs ("Running light
without overbyte!").

"jealous xmp" <jealousxmp@aol.commonplace> wrote in message
news:20040409182117.11269.00000106@mb-m15.aol.com...
> I basically have 3 questions.
>
> Are there any groups devoted to homebrewing CPU's and building computers
from
> microprocessor and chip level?  I've found a few web sites and threads
related
> to FPGA CPU and building from 7400 level circuitry, but haven't found a
web
> forum or Usenet group yet.  I have no desire to build a complete computer,
just
> interested in the basic design and its application to my projects.
>
> Are there any kits left similar to the AES ones where you program on a hex
> keypad in assembly?  I've found some vendors but the kits are either high
> priced or meant for wholesale to educators.  I've seen a few dated kits on
> Ebay, unfortunately at high prices due to collectors.  Is there a present
day
> analog to these kits?  I have some fond memories of "coding" on
> microcontrollers as a kid, and would like to try it again.  I realize this
has
> little practical value, this is just for fun.
>
> Any suggestions for a cheap (e.g. $50 to $150) simulator or development
kit for
> learning the basics?  I thinking Basic Stamp might be a start.  I'd like
to
> avoid c, and use basic, forth, or some such.  I'm not sure why I'm biased
> against c but I am, and another language would be preferred.
>
> Michael

For forth have a look at www.newmicros.com

Also have some new boards that are similar to a basic stamp but
a lot more powerful.
http://www.newmicros.com/cgi-bin/store/order.cgi?form=prod_detail&part=PlugaPod_DKit

The new tiny arm boards may suit you as well.
http://www.newmicros.com/cgi-bin/store/order.cgi?form=prod&cat=tiniarm
http://www.newmicros.com/cgi-bin/store/order.cgi?form=prod_detail&part=TiniARM_DKit

comparison of their pod boards using the motorola dsp5680x board features
http://www.newmicros.com/store/product_details/podmatrix.html

For cheap boards have a look at futurlec.com
http://www.futurlec.com/BasicControllers.html
http://www.futurlec.com/TrainingBoards.shtml
http://www.futurlec.com/DevelopmentBoards.html

maybe one of the avr or 8051 boards + the demo version
of bascom avr or 8051 basic compilers

can get the demo versions of bascom avr and bascom 8051
http://www.mcselec.com/

The dontronics simmsticks are quite good as well
but require you to assemble(solder them)
www.dontronics.com

for forth with a microchip 16f877 pic see picforth
http://www.rfc1149.net/devel/picforth

tutorials
http://tutor.al-williams.com/
http://tutor.al-williams.com/picforth1.htm

Alex

In article <clee70hpvqeodlv7dcq3nsaoqfvct41su1@4ax.com>,
Ben Bradley <ben_nospam_bradley@mindspring.example.com> wrote:
>In comp.arch.embedded, jealousxmp@aol.commonplace (jealous xmp) wrote:
>
>>I basically have 3 questions.
>>
>>Are there any groups devoted to homebrewing CPU's and building computers from
>>microprocessor and chip level?  I've found a few web sites and threads related
>>to FPGA CPU and building from 7400 level circuitry, but haven't found a web
>>forum or Usenet group yet.  I have no desire to build a complete computer,
>[ ... ]
>>Are there any kits left similar to the AES ones
>
>   What's AES? I only know of Audio Engineering Society, and that's
>obviously not it from the context.
>
>>where you program on a hex
>>keypad in assembly?

   I don't know if this is a propos, but I've just got
involved with an open source PIC project that might be
interesting to a tinkerer:

        http://www.interaccess.org/aid/

with some C source, board schematics and construction tips.

        Regards.        Mel.

jealous xmp wrote:
> 
> I basically have 3 questions.
> 
> Are there any groups devoted to homebrewing CPU's and building computers from
> microprocessor and chip level?  I've found a few web sites and threads related
> to FPGA CPU and building from 7400 level circuitry, but haven't found a web
> forum or Usenet group yet.  I have no desire to build a complete computer, just
> interested in the basic design and its application to my projects.

I started off in the early 70's building a kit that had leds and
switches for program input, but you don't have to do that today. They
have made life much easier. :-)

have a look at:
http://www.dontronics.com/auto.html
for a general rundown, then
http://www.dontronics.com/dt006.html
for a very simple kit, and:
http://www.dontronics.com/stk500.html
http://www.dontronics.com/staver.html
for assembled and tested methods of doing things.
None of them expensive.

Cheers Don...


-- 
Don McKenzie
E-Mail Contact Page:      http://www.e-dotcom.com/ecp.php?un=Dontronics

USB to RS232 Converter that works http://www.dontronics.com/usb_232.html
Don's Free Guide To Spam Reduction  http://www.e-dotcom.com/spam_exp.php

>Sounds like you might possibly be >interested in PICs, AVRs, or maybe the
>TI MSP430 instead.  

Thanks for all the suggestions that were given by various people.  I think I
will try one of the development kits.

I do have some old breadboards and a medium-sized parts bin.  So once the chip
is programmed I can potentially drop it in some sort of test project.  I'm not
too good with chip soldering, but that's something I wanted to learn anyway.

Michael