Re: [Amforth-devel] Atmega1280

[Matthias T. <mt...@we...>]

Andy,

>
> What can I say, you are all stars.

Thank you very much, but whats a star without the universe? ;=)
amforth got most of it's features from user feedback (anything from
within complaints and patches).

> The one processor that was short for me was the 1280 (Arduino Mega)
> which is pretty much a 640 but with 128k of memory instead of 64k. I am
> just about to set too and have a go at compiling for the 1280 and will
> mod the 640 file (I assume this is still the way to go, although the
> headers claim that the files are auto generated)

The files are generated with the pd2amforth utility, but edited
afterwards,
there is no complete toolchain to implement the files for a new controller
type. The manual changes are mostly trivial however...

> Questions.
>
> Who do I need to feedback difs changes tweaks etc to to get the  final
> 1280 dev files into the distribution (at some point) ??

Just send them to me directly. There is a patch tracker at the
sourceforge project site as well, it will reach me either way..

>
> Which variables do I need to tweak to increase the memory size?? (a
> quick win hopefully, for my first attempts)

You may use the at90can128 file as a starting point since it already
has all the changes needed for the 128KB flash [1]. Another hint is: use
the usart words with polling access. The interrupt driven IO may
sometimes be very frustrating to get working.

Then there should be only a very few addresses to check:
Usart ports, RAM start/end NRWW start address. Anything else
should be left unchanged. At least for the first try ;=)

Matthias

[1] The 128KB flash are seen as 64KWords to fit into the 16bit address
range, and there are a few other instructions to use. And finally the big
atmegas are slightly slower when accessing the flash since they need
to execute more instructions. But thats all hidden inside a few macros.