New ADB Soundbox replacement

Started by barcher174, March 04, 2018, 08:46:41 am

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barcher174

Quote from: "Andreas"
Quote from: "barcher174"Either way, the video is probably not very useful anyway.


As far as i understood, this board makes it possible to power on a Turbo slab and use it with (Apple)? ADB keyb/mouse and VGA video - or not?
So i think the video-out is essential.


Yes, your understanding is correct. The problem is almost certainly with my cable. The Next original 19pin cable I have with no ADB connection displays fine. Rob is sending me one of the later cables with ADB to verify.

barcher174

I received a proper cable from Rob today:

Part number: 4535.00

I had forgotten that even with B&W, the ADB connection makes the monitor run at a weird 72.5hz which my LCD can process, but not well. Trying another monitor I get a crystal clear image.

So the good news is that everything is working as expected now.

On the non-ADB front, I received parts this week to start a prototype. Based on what I've learned in the past week I'm feeling pretty confident that we can replace the soundbox entirely.

My plan is to use a rasperry pi to prove the communication protocol. While it's weird to use a computer to boot a computer, we can look into replacing it with a more compact solution after we have proof of concept.

hideehoo

Any plans on making the project files or gerbers available?  Just picked up a Mono Turbo without a monitor and looking for a cheap way to get it up and going.

barcher174

I've still been working on this in my spare time. I put a socket for the custom ASIC which is found in both the first revision megapixels and all B&W laser printers. The board can now optionally do nonADB when this chip is installed, otherwise it does just ADB. Eventually I hope to replace the ASIC with my own implementation.



I made a few mistakes which I've corrected on the bottom (I rushed to get it done to coincide with some time off. Never rush it...), so I plan of doing one more spin.  

The drakenware solution looks much further along than mine (hopefully almost done?) so I don't feel any pressure to finish quickly. I'm going to keep working on this just for the fun of it.

krazycat

Good job! The online port solution is certainly more practical than the previous revision of the board.
With the ports aligned on one side, it will be easier to find a suitable case for this board, or print a 3D replica of the original SoundBox case.

msch

great project -  Congrats!
I would like to buy one if still available.
Mathias

--
WTB: Next cube - please contact me if You want to sale.

Waltermixxx

Wow, what a great project.  Perfect for those who who just want to play around with a slab.  Are these boards going to be available for sale?
would love to play around with one. :)

Cheers.

barcher174

I sent a batch to Rob at blackhole and I believe they are currently still available for sale.

barcher174

I figured out how to pass the sound test using the NeXT ASIC. The ASIC requires a 8.4672MHz clock signal applied to pin 5 to verify the sound circuit is complete. I made a simple clock circuit to test:



For anyone interested I'm collecting pinout information here:
http://www.asterontech.com/Asterontech/S38GC008PB02.html