Heathkit ETA-3400 vs. ETW-3400 confusion?

william degnan billdegnan at gmail.com
Sun Jun 5 23:42:34 CDT 2016

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.

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