DFB1r4 design discussion thread

[Steve]

Amazing work @Badwolf :) So glad you're making progress!

[Badwolf]

Amazing work @Badwolf :) So glad you're making progress!

Thanks, Steve!

Unfortunately I just discovered another design boo-boo which torpedoes this batch of boards, though.

I was scratching my head as to why the full 64MB could pass the memory tests with YAARTTT, but then everything would go to custard when I tried to add AltRAM: I've inadvertently put a byte 3 line to the byte 4 port of one of the memory chips (and vice versa)! :|

Basically with D23 and D31 swapped, word and longword writes will succeed fine but byte writes to either byte 3 or byte 4 of the port will fail as it will be latching one line from the other byte instead. YAARTT only ever performs word writes, so this wasn't a problem.

Bah!

I hope I can cut these two traces and patchwire this board for continued dev, but with three patch wires on the board already, I think it's going to need a respin before I get a release version.

Damn and blast.

BW

[exxos]

I feel your pain there!

We need a group hug smiley. But I guess this one will just have to do.. :chairsmack:

[JezC]

I feel your pain there!

We need a group hug smiley. But I guess this one will just have to do.. :chairsmack:

I thought you'd added this one :awwww: for these situations?
:wink: :lol: :roll: :hide: :fire: :fire: :fire:

[Badwolf]

We need a group hug smiley. But I guess this one will just have to do.. :chairsmack:

I thought you'd added this one :awwww: for these situations?

It's interesting how Chris' mind goes straight to the chair whack, ain't it? :lol:

BW

PS: here's the oopsie.

Screenshot 2021-09-24 at 15.28.30.png

[JezC]

It's interesting how Chris' mind goes straight to the chair whack, ain't it? :lol:

BW

Also, if you read TF's reply to my post on his general letter topic, that puts it in a totally different light! :lol:

[Badwolf]

Also, if you read TF's reply to my post on his general letter topic, that puts it in a totally different light! :lol:

:twisted:

[JezC]

Also, if you read TF's reply to my post on his general letter topic, that puts it in a totally different light! :lol:

:twisted:

And then the latest response to that from @exxos :hide:

General question: does :hide: invalidate the :chairsmack: smilie?

[exxos]

General question: does :hide: invalidate the :chairsmack: smilie?

Nope.. You get hit over the head with the chair your under..


:threadjacked:

[Badwolf]

OK, my shonky design confirmed.

IMG_4747 2.jpeg

IMG_4749.jpeg

IMG_4748.jpeg

(All these at 16MHz)

Now, how fast can we get this to go..?

BW