Hi Art - nice to see someone still interested in the old '70s 6800
stuff! I also had a SWTP back in those days, followed up with a 6809
and then 68000 system. I still have some of that stuff running, so I'm
not planning to do any expansion on the ET-3400. But it does have
potential for doing some simple embedded stuff that has to run faster
than a Basic Stamp or Picaxe could do. I used to have a batch of
experiments for the ET-3400, but right now I can only find one - a
simple 4-bit D-to-A circuit that generates a simple random wave.

I don't have much of my old 6800 software any more, but I have a pile
of 6809 and 68000 stuff here that I wrote and am willing to put on the
web in source code version. I've already done some of that (see
www.cloud9.net/~stark). When you get to the point where you have some
hardware to run it on, let me know. I did have a 6800 monitor called
HUMBUG, which was a substantial improvement over MIKBUG, but I'm not
sure I could find the code any more.

I do have a 68HC11 version of my DOS up and running, and it should run
with just minor changes on a 6800 or 6808. It uses a CF card as a
drive, and is program conpatible with Flex and SK*DOS / STAR-DOS
software from that era.

Pete


--- In ET-3400@yahoogroups.com, "Granz" <granz_consult@...> wrote:

> I am currently saving up the parts to put 32K RAM, 8K EEPROM, PIA
(with MikBug compatible Serial I/O) on a PCB and porting MikBug to my
ET-3400 in 1K of the EEPROM.... <snip> ....  Would like to see some
simple apps which would have been run on that kind of system (a la
SWTPC, etc) back in the late '70s.
>
> Now all I need is some spare time to play with that.
>
> Art

--- In ET-3400@yahoogroups.com, Whipaway <whipaway@...> wrote:
>
> That's good information to know!
> Maybe you should do a writeup on the modification and place it into
the files section.

There isn't much to say - if you bend up the appropriate pin of the IC
(and only that one), it will decode that range of addresses. For
instance, suppose you put a scope on pin 5 of IC2, and run this program:
    START LDAA $8000   0000  B6 8000
          JMP START    0003  7E 0000
then each time the loop runs, you will get a short negative-going
spike on that IC2 pin.

Another simple example: Take a 7474 type D flip-flop, connect to
power, connect its D input to D0, and connect its clock input to IC2
pin 5. Feed the Q output of the flip-flop to an LED. Now do EXAM 8000
followed by CHANge 01. The flip-flop will set and the LED lights. Do
CHANge 00, the flip-flop will reset, and the LED goes off. You've just
built a simple 1-bit output port.

Pete

--- In ET-3400@yahoogroups.com, "Granz" <granz_consult@...> wrote:
>
> Prof,
>
> Excellent!  Great idea.  I also used to teach using the ET-3400,
and got my own a while back.
>
> I am currently saving up the parts to put 32K RAM, 8K EEPROM, PIA
(with MikBug compatible Serial I/O) on a PCB and porting MikBug to
my ET-3400 in 1K of the EEPROM.(have RAM, EEPROM, decoder ckts ('138
and/or '154s) and PIA, waiting to run across the timing chip
(MC14536) for the serial baud rate generator)  I wanted the PIA to
be addressed at 8000H and the EEPROM just below the '3400's ROM.
Your tip will make that first part a bit simpler.
>
> The user will get into MikBug by using the on-board monitor to
jump to MikBug.  Will use a notebook as a simple Serial Terminal.
Ideally, this will have a BASIC (maybe tiny or maybe bigger) and
possible even add an IDE controller for a CF card (saw an interface
on an 1802 site that only uses 3 chips (http://www.elf-
emulation.com/hardware/ide8.html) - could write a BIOS for an OS or
maybe write a simple OS myself.
>

Interesting idea, using both monitors in one system.

There are a few apps for SWTPC 6800 systems out there.  Notably, a
Star Trek game called "Space Voyage" by TSC,  and a few Basic
interpreters.  I have a SWTPC machine too, but I don't use it much
as the I/O is dreadfully slow (300 baud cassette, and 1200 console)
and I haven't got around to tinkering with it to speed things up.
And I need to write some Xmodem code for the 6800, so I don't have
to endure the inefficient ASCII-based Motorola S files. (That's
another reason it's so slow - everything takes twice as long as it
should because the S files were designed for ASCII only Teletypes
with 7 bits instead of 8)  Speed isn't usually a problem
for "educational" uses where you're usually loading small programs.
But load a 12K file, and you'd better bring a sandwich.

-John

-John

----- Original Message -----

From: prof_stark

To: ET-3400@yahoogroups.com

Sent: Friday, January 09, 2009 10:07 PM

Subject: [ET-3400] Re: Hello!

Hi Art - nice to see someone still interested in the old '70s 6800
stuff! I also had a SWTP back in those days, followed up with a 6809
and then 68000 system. I still have some of that stuff running, so I'm
not planning to do any expansion on the ET-3400. But it does have
potential for doing some simple embedded stuff that has to run faster
than a Basic Stamp or Picaxe could do. I used to have a batch of
experiments for the ET-3400, but right now I can only find one - a
simple 4-bit D-to-A circuit that generates a simple random wave.

I don't have much of my old 6800 software any more, but I have a pile
of 6809 and 68000 stuff here that I wrote and am willing to put on the
web in source code version. I've already done some of that (see
www.cloud9.net/~stark). When you get to the point where you have some
hardware to run it on, let me know. I did have a 6800 monitor called
HUMBUG, which was a substantial improvement over MIKBUG, but I'm not
sure I could find the code any more.

I do have a 68HC11 version of my DOS up and running, and it should run
with just minor changes on a 6800 or 6808. It uses a CF card as a
drive, and is program conpatible with Flex and SK*DOS / STAR-DOS
software from that era.

Pete

--- In ET-3400@yahoogroups.com, "Granz" <granz_consult@...> wrote:

> I am currently saving up the parts to put 32K RAM, 8K EEPROM, PIA
(with MikBug compatible Serial I/O) on a PCB and porting MikBug to my
ET-3400 in 1K of the EEPROM.... <snip> .... Would like to see some
simple apps which would have been run on that kind of system (a la
SWTPC, etc) back in the late '70s.
>
> Now all I need is some spare time to play with that.
>
> Art

I've poked around here a bit, but can't seem to find a list of the
parts for experimenting on the proto board.
I've come back to starting over with my rig, bought when it came out,
to find that I had robbed it of a part long ago. Then I put it away
'till I get around to it'.

I'm sure I have the buttons and other unique parts, but need the list
of 7400, xistors, resistors to play with.

I would like to go through he whole course again. At one time I had
hooked up the interface accessory unit to a Centronics 101al printer,
and remember doing the Lunar Lander game on video.

I first robbed it to double the memory of my Ohio Scientific c24p
computer from 4k to 8k, which still runs.

I would like to progress through the course, then start from scratch
on my Hero1 'bot.
Thanks for supporting my memories. Pun intended.

I've poked around here a bit, but can't seem to find a list of the
parts for experimenting on the proto board.
I've come back to starting over with my rig, bought when it came out,
to find that I had robbed it of a part long ago. Then I put it away
'till I get around to it'.

I'm sure I have the buttons and other unique parts, but need the list
of 7400, xistors, resistors to play with.

I would like to go through he whole course again. At one time I had
hooked up the interface accessory unit to a Centronics 101al printer,
and remember doing the Lunar Lander game on video.

I first robbed it to double the memory of my Ohio Scientific c24p
computer from 4k to 8k, which still runs.

I would like to progress through the course, then start from scratch
on my Hero1 'bot.
Thanks for supporting my memories. Pun intended.

Wow, don't remember the PIA 6820 in the kit. Is it similar to the 6520
PIA used in the C-64? If so I can rob one from one of mine, as they
are hard to find. If it is the same one, then it will be in some of my
pinball machines too.
Thanks for the info. I have the flip chart, and I believe the
cassettes. I want to relive from the first lessons, I have notes from
in '81. I used my TI-59 programming sheets for the et/a-3400.

Hi all,
I am a retired graphic designer with over 20 years in the field. I am
enjoying my newfound free time by learning things I missed during my
tenure in computer world.

I have been reading with great interest Makezine and some of their
projects involved programming on a microprocessor level.

I bought a Heathkit 3400 in the hopes of getting some background
knowledge in this area.

My Heathkit did not come with any documentation. I found online
documentation for assebling the 3400 and for using the I/O interface (I
do not have). Other than that, I am at a complete loss where to begin.
Any guidance would be appreciated. Please remember, VERY green
beginner.

--- In ET-3400@yahoogroups.com, "nhtome" <nhtome@...> wrote:
>
> Wow, don't remember the PIA 6820 in the kit. Is it similar to the 6520
> PIA used in the C-64? If so I can rob one from one of mine, as they
> are hard to find. If it is the same one, then it will be in some of my
> pinball machines too.

I think you are mixing up several chips here... there are a pair of
6526 CIAs in the C-64, but the 6520 did appear in the PET and is very
much compatible with the Motorola 6821 PIA.  The 6820 PIA is an older
version of the 6821 PIA, so it would probably be a good idea to
cross-check for differences.  6821s are not that difficult to find.

-ethan

On Thursday 19 February 2009 02:02:27 pm erd_6502 wrote:
> --- In ET-3400@yahoogroups.com, "nhtome" <nhtome@...> wrote:
> > Wow, don't remember the PIA 6820 in the kit. Is it similar to the 6520
> > PIA used in the C-64? If so I can rob one from one of mine, as they
> > are hard to find. If it is the same one, then it will be in some of my
> > pinball machines too.
>
> I think you are mixing up several chips here... there are a pair of
> 6526 CIAs in the C-64, but the 6520 did appear in the PET and is very
> much compatible with the Motorola 6821 PIA.  The 6820 PIA is an older
> version of the 6821 PIA, so it would probably be a good idea to
> cross-check for differences.  6821s are not that difficult to find.
>
> -ethan

Yup.  I have lots of 6526s,  and 6522s,  if anybody needs some,  along with a
whole lot of other salvage/NOS from the c64, 1541, etc.


--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

Recently I found my old ET in the garage. It is still working. One key (the "D")
is missing. It is wired for 220 volts, but there should be no problem to convert
it to 120 volts according to the schematic. The unit is now in Germany. If you
are interested, I will look for shipping costs.

From this point on, any new members that join this group will automatically have
their messages moderated and reviewed before being able to post.

I was wondering if anyone has a handy list (or no where I can locate the correct
document) for the ET-3400A monitor ROM's subroutines...like outputting bytes to
the display, the addresses of the data i/o memory mapped I/O chips, and other
necessary things to really take advantage of the stuff built into the ET-3400A.

Thanks

Mike

Between the power experimenter strip and the keyboard and below the
experimentr's breadboard strip are two chips separated by what appears to be the
holes for a multi-pin flat cable connector (not installed).

Is that to connect to an add-on device (the monitor-I/O board that talks to a
dumb terminaL?)

Are the two chips data buffers for the data lines?

Thanks for the help

Mike

On Thu, Apr 30, 2009 at 4:22 PM, Michael <mcrawford01@...> wrote:
> Between the power experimenter strip and the keyboard and below the
experimentr's breadboard strip are two chips separated by what appears to be the
holes for a multi-pin flat cable connector (not installed).
>
> Is that to connect to an add-on device (the monitor-I/O board that talks to a
dumb terminaL?)

The external peripheral I know of (but do not own myself) is a memory
box, but there's no reason you couldn't add more than just memory.

To talk to a dumb terminal, you'd need a UART (or software routines to
simulate one) and EIA level drivers (like the common 1488/1489 chips).
  I don't recall if the external box was wired for one of those by
default or not, but it certainly sounds like an obvious add-on
feature.

> Are the two chips data buffers for the data lines?

I'd have to check my ET-3400, but that sounds right.  It's in the
schematics, plus ISTR they are TTL chips ordinarily used for buffers.

-ethan

Check the ET-3400 schematics in the FILES section for the pinouts of the
expansion connector, which would allow you to connect to an ETA-3400.
The schematics for the ETA-3400 are also in the Files section, should you decide
to build one.
--- In ET-3400@yahoogroups.com, "Michael" <mcrawford01@...> wrote:
>
> Between the power experimenter strip and the keyboard and below the
experimentr's breadboard strip are two chips separated by what appears to be the
holes for a multi-pin flat cable connector (not installed).
>
> Is that to connect to an add-on device (the monitor-I/O board that talks to a
dumb terminaL?)
>
> Are the two chips data buffers for the data lines?
>
> Thanks for the help
>
> Mike
>

On Thu, Apr 30, 2009 at 5:27 PM, Ethan Dicks <ethan.dicks@...> wrote:
> On Thu, Apr 30, 2009 at 4:22 PM, Michael <mcrawford01@...> wrote:
>> Between the power experimenter strip and the keyboard and below the
experimentr's breadboard strip are two chips separated by what appears to be the
holes for a multi-pin flat cable connector (not installed).
>>
>> Are the two chips data buffers for the data lines?
>
> I'd have to check my ET-3400, but that sounds right.  It's in the
> schematics, plus ISTR they are TTL chips ordinarily used for buffers.

I am incorrect - the buffers are above the 40-pin connector.  The
chips below the connector (U1 and U2?) are at least a 7442 (1-of-10
decoder) and something else that's not a buffer.  The 7442 is probably
for generating chip selects through a range of RAM - check the pinout
of the connector on the schematics to be sure.

-ethan

My son is in College working on an Engineering degree.  He recently read that
there is a severe lack of engineers with programing skills.  I told him about my
ET-3400 and the Microprocessor course I used to teach, and so he is interested
in going through the entire Heath course for the ET-3400, so I priced out the
items required (hopefully I didn't miss anything - if I did, please let me
know).  If you don't have anything at all on the list, it will only cost U$42.03
plus shipping from Jameco (I could not find the 9368 chip there, but you can
either skip that experiment or get it from somewhere else - I just like one-stop
shopping)  I also assumed that everyone in this group would have or be able to
find some hook-up wire and of course, the ET-3400 itself.

Oh, I forgot to mention that if you do not have any of the resistors and do not
need a large supply, it may be better to get a resistor assortment kit (103166
or 10664 both have all the resistors you need for the experiments, including the
R/2R resistor network to take the place of the obsolete MC1406 on page 10-98). 
If you have the resistors for the R/2R network or you have a D/A convertor, then
the 10720 kit will be the cheapest and greatest variety you can get.

Art

--- In ET-3400@yahoogroups.com, "granz_consult" <granz_consult@...> wrote:
>
> My son is in College working on an Engineering degree.  He recently read that
there is a severe lack of engineers with programing skills.  I told him about my
ET-3400 and the Microprocessor course I used to teach, and so he is interested
in going through the entire Heath course for the ET-3400, so I priced out the
items required (hopefully I didn't miss anything - if I did, please let me
know).  If you don't have anything at all on the list, it will only cost U$42.03
plus shipping from Jameco (I could not find the 9368 chip there, but you can
either skip that experiment or get it from somewhere else - I just like one-stop
shopping)  I also assumed that everyone in this group would have or be able to
find some hook-up wire and of course, the ET-3400 itself.
>

There might be more ifo here:
http://www.classiccmp.org/dunfield/heath/et3400.pdf

--- In ET-3400@yahoogroups.com, Michael Crawford <mcrawford01@...> wrote:
>
> A misunderstanding I expect.  I;m from Intel world, so perhaps it is my
background that is screwing me up.
>
> I am not running tiny basic or a terminal connected to the 3400A.  I am using
the keyboard and doing very simle programs entering (groan) hex code for each
operation and operand.
>
> The ROM at FC00 has a few simple routines for displaying digits on the hex
display, from a byte to a whole string of characters (6 one would presume).  I
am disassembling some sample code fragments trying to figure out how the stuff
works...for instance, there is also a memory map for the actual segments of the
six 7 segment displays, starting at C110 (C110H to C117H controls the 7 hex
display line segments a thru g plus the decimal point) and going to C167.
>
> I've included what I have figured out in an HTML file so far.  If you take a
look, you'll see it is not at all complete.  I need the entry points (BSR to
specific routines) and the parameters that control what the subroutines in the
ROM do when called.  I have not seen in the files the yahoo group has online,
anything that gives actual instructions or a table on how to call the "built-in"
subroutines in the FC00 ROM.
>
>  Intel's SDK boards had such a listing, helping the users quickly write quick
little test routines without having to connect to a terminal (a lot of
microcontroller apps don't ever connect to a terminal).  Anywho, I guess I am
looking to save some time in more disassembly and analysis of sample routines. 
>
> What I need is a listing of the FC00 assembly code, similar to that you gave
me the link to, but for the FC00H ROM instaed of the tinybasic/terminal
monitor/FANTOM II ROM(s).
>
> Thanks
>
> Mike
>
>
> --- On Sat, 5/2/09, craig richardson <craig.a.richardson@...> wrote:
>
> From: craig richardson <craig.a.richardson@...>
> Subject: Re: [ET-3400] Rom Subroutines
> To: ET-3400@yahoogroups.com
> Date: Saturday, May 2, 2009, 3:52 AM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>       Here's a link to the monitor listing online. Perhaps it doesn't cover
the 3400A...not sure, but it's a start.
>
> http://www.classicc mp.org/dunfield/ heath/e34miosw. pdf
>
>
> On Thu, Apr 30, 2009 at 4:19 PM, Michael <mcrawford01@ yahoo.com> wrote:
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>       I was wondering if anyone has a handy list (or no where I can locate the
correct document) for the ET-3400A monitor ROM's subroutines. ..like outputting
bytes to the display, the addresses of the data i/o memory mapped I/O chips, and
other necessary things to really take advantage of the stuff built into the
ET-3400A.
>
>
>
>
> Thanks
>
>
>
> Mike
>

I'm not seeing the images, can you resend as a pdf?
--- In ET-3400@yahoogroups.com, Michael Crawford <mcrawford01@...> wrote:
>
> Here is the final version of the ET-3400 "FC00 ROM" subroutines for
manipulating the hex displays.   This might be useful to anyone who wishes to
generate feedback or results while running code on the trainer.  Maybe you could
store this in the file section?
>
> - Mike
>
>
> --- On Sun, 5/3/09, whipaway <whipaway@...> wrote:
>
> From: whipaway <whipaway@...>
> Subject: [ET-3400] Re: Rom Subroutines
> To: ET-3400@yahoogroups.com
> Date: Sunday, May 3, 2009, 4:46 AM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>       There might be more ifo here:
>
> http://www.classicc mp.org/dunfield/ heath/et3400. pdf
>
>
>
> --- In ET-3400@yahoogroups .com, Michael Crawford <mcrawford01@ ...> wrote:
>
> >
>
> > A misunderstanding I expect.  I;m from Intel world, so perhaps it is my
background that is screwing me up.
>
> >
>
> > I am not running tiny basic or a terminal connected to the 3400A.  I am
using the keyboard and doing very simle programs entering (groan) hex code for
each operation and operand.
>
> >
>
> > The ROM at FC00 has a few simple routines for displaying digits on the hex
display, from a byte to a whole string of characters (6 one would presume).  I
am disassembling some sample code fragments trying to figure out how the stuff
works...for instance, there is also a memory map for the actual segments of the
six 7 segment displays, starting at C110 (C110H to C117H controls the 7 hex
display line segments a thru g plus the decimal point) and going to C167.
>
> >
>
> > I've included what I have figured out in an HTML file so far.  If you take a
look, you'll see it is not at all complete.  I need the entry points (BSR to
specific routines) and the parameters that control what the subroutines in the
ROM do when called.  I have not seen in the files the yahoo group has online,
anything that gives actual instructions or a table on how to call the "built-in"
subroutines in the FC00 ROM.
>
> >
>
> >  Intel's SDK boards had such a listing, helping the users quickly write
quick little test routines without having to connect to a terminal (a lot of
microcontroller apps don't ever connect to a terminal).  Anywho, I guess I am
looking to save some time in more disassembly and analysis of sample routines. 
>
> >
>
> > What I need is a listing of the FC00 assembly code, similar to that you gave
me the link to, but for the FC00H ROM instaed of the tinybasic/terminal
monitor/FANTOM II ROM(s).
>
> >
>
> > Thanks
>
> >
>
> > Mike
>
> >
>
> >
>
> > --- On Sat, 5/2/09, craig richardson <craig.a.richardson @...> wrote:
>
> >
>
> > From: craig richardson <craig.a.richardson @...>
>
> > Subject: Re: [ET-3400] Rom Subroutines
>
> > To: ET-3400@yahoogroups .com
>
> > Date: Saturday, May 2, 2009, 3:52 AM
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >       Here's a link to the monitor listing online. Perhaps it doesn't cover
the 3400A...not sure, but it's a start.
>
> >
>
> > http://www.classicc mp.org/dunfield/ heath/e34miosw. pdf
>
> >
>
> >
>
> > On Thu, Apr 30, 2009 at 4:19 PM, Michael <mcrawford01@ yahoo.com> wrote:
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >
>
> >       I was wondering if anyone has a handy list (or no where I can locate
the correct document) for the ET-3400A monitor ROM's subroutines. ..like
outputting bytes to the display, the addresses of the data i/o memory mapped I/O
chips, and other necessary things to really take advantage of the stuff built
into the ET-3400A.
>
> >
>
> >
>
> >
>
> >
>
> > Thanks
>
> >
>
> >
>
> >
>
> > Mike
>
> >
>