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ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 9:09 am
by terriblefire
This board is designed to allow me to re-engineer Agnus (cycle exact) and enable us to build Amigas into the future.

It was built out of necessity to get me a 8372AB for my ReA3000. But i should be able to reassign the pins for other Agnus revisions (provided the power pins are always the same).

Design is an ICE40HX4K FPGA + Level Shifters. It solders into a PLCC TH socket like Megachip. I'm sure someone will ask why I didnt put ram on here.. Simple. I'm a purist. I want this chip to replace Agnus and nothing else.
reagnus.JPG
reagnus.JPG (173.08 KiB) Viewed 16601 times
Should be possible to tweak the design it to any PLCC part for ST's and Amigas.

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 9:24 am
by PhilC
Looking good so far @terriblefire .

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 10:45 am
by go0se
This looks great!

Would you need to 45 degree chop the (bottom left of the PCB if I've got my install orientation correct...) corner of the board edge where the (c) is in order to clear the cap (C816 on Rev8a board.) on an A500+ ?. Pulling that cap flat as in the picture below is not always possible.

Screenshot from 2020-05-26 10-32-53.resized.png
Screenshot from 2020-05-26 10-32-53.resized.png (641.94 KiB) Viewed 16571 times

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 12:14 pm
by dalek
OMG that would be fantastic! I've always been worried what would happen if the one in my A3000 died :(

The other good (bad!) thing about that Agnus is it's the one people stole to give Rev 6 A500's 2MB chip RAM.

Also please double the RAM from 0MB to 0MB.

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 12:51 pm
by 8 Bit Dreams
Awesome news!!
:excited: :excited: :excited: :cheer:

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 12:58 pm
by arkadiusz.makarenko
Wow.
Is this chip £5 or am I missing something?

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 1:07 pm
by terriblefire
arkadiusz.makarenko wrote: Tue May 26, 2020 12:58 pm Wow.
Is this chip £5 or am I missing something?
Yes. Its £4.18 + vat :)

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 1:59 pm
by EzdineG
I’ll take one for my A1000, please :?

Wouldn’t that be something?

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 2:18 pm
by terriblefire
Well the board is easy. Firmware will be the pain.

But i'll do a run once i get something working.

Re: ReAgnus Board (Design Complete)

Posted: Tue May 26, 2020 4:41 pm
by Maximilian
Thaty is an amazing project, :D
(wasn't someone else doing the same?)

Are there any pins over on the FPGA and the bus buffers?
If wired to a couple of pads those could be used for upgrades or feature selection like Pal/Ntsc.
Just a thought..