Heathkit ETA-3400 vs. ETW-3400 confusion?

drlegendre . drlegendre at gmail.com
Mon Jun 6 00:21:07 CDT 2016

And as good a guess as any, so far..

It seems my box has both the monitor and tiny basic ROMs on-board.. or at
least, it seems that the requisite chips are present. Until I can come up
with a 2x20 pin header, to connect my ET-3400A, I won't really know.

I did put out a request to the list for a header, but no one has offered
up. Looks like I need to go ahead and order up (more than I need) from eBay
or someplace. I don't even have a junk mobo to plunder - and even so, I'd
be lucky to get one removed in decent shape. They really aren't made for
that kind of re-use.

On Sun, Jun 5, 2016 at 11:42 PM, william degnan <billdegnan at gmail.com>

> On Sun, Jun 5, 2016 at 11:12 PM, drlegendre . <drlegendre at gmail.com>
> wrote:
> > Bill,
> >
> > Thanks, nice little site you made there. I also lack the correct ribbon
> > cable, so it seems my mod will use a plain gray ribbon.. and so long as
> > it's installed correctly, that should be just fine. ;-)
> >
> > Thing is, it still doesn't answer my main question.. Your expansion accy.
> > is screened 'ETA-3400' and mine is screened 'EWA-3400'.
> >
> > They seem to share the same board & components, so why the two different
> > marks - is there any material difference? I see that yours has some
> > switches on the front panel, but I assume that those are for your custom
> > serial comms. mod.
> >
> >
> Oops I did not notice the ETA- vs EWA-
> It could be that T = Tiny BASIC and W = Wintek Monitor (only).  i.e. you
> need to find a BASIC ROM if you want to make it an "ETA".  There should be
> no reason not to be able to load BASIC into memory via the serial port if
> you don't have a BASIC ROM.  I believe you'd put it into 0010-00C7.  You'd
> need 0000-0009 (?) and 0100-0FFF to be read/write.
> The monitor starts at 1C00, uses upper memory.
> This my guess.

More information about the cctech mailing list