NeXT ADB soundboard to NON ADB conversion?

Started by Rob Blessin Black Hole, May 08, 2014, 08:23:08 am

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barcher174

Yes. I have tested with an 030 cube and it is working without a problem.

https://www.dropbox.com/s/or2ott08bzm6017/IMG_0576.JPG

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Brian

barcher174

Full details here:

https://www.dropbox.com/s/g27eqfy08oq06pz/Next%20ADB%20Convertion.pdf

--
Brian

Rob Blessin Black Hole

Hello Brian Archer : Thanks a million .... A couple things that will be interesting to test with the modified adb to non adb board .
Looks like it works with earlier version of the rom back to 030, earlier monitor cables .
if you unplug the non adb keyboard from the modified adb soundbox and plug it back in does it synche back up with non Adb? As adb once disconnected won't reconnect may be it has to do with the non adb components talking to the ASIC.
I have a ton of new adb soundboards and new non adb keyboard connectors as well as soundbox shells the conversion works with earlier roms that is way cool.
I'm ready to solder and cut traces lol but probably need an arrow on the photos also if you need any adb soundboards to tinker with I can send you a few free of charge with the shells and connectors for you efforts.
Can a soundboard be both adb and non adb compatible ... 2 keyboard connectors and a toggle switch ... I'm guessing it would have to close and open the modified circuits with wizardry .
The soundboards all used the same speaker , will other speakers work without damaging the board?
Does the microphone and sound work on the modified board ?
For the modified 152 would it be possible to add an outlet (gfci?) internally in the cube to plug in the flatpanel or other peripherals like a wireless buffalo router and safely create load ?  
You the man

Quote from: "barcher174"I'm just going to let these speak for themselves....

https://www.dropbox.com/s/6cpz880uc5omshy/IMG_0574.jpg

https://www.dropbox.com/s/0bquepf1h02u26n/IMG_0575.JPG

YES. That is an ADB soundboard working with a non-ADB keyboard and mouse. We have a solution. I'll work on a formal write-up with some pics and do a bit more testing to be sure it's stable.



So to sum up:

1) Machines that currently use ADB sound boxes -do not- need the soundbox to function. If you can live without sound you can hook an ADB keyboard directly to pin 7 of the 19 pin connector.

2) If you have an ADB sound board it can be converted to non-adb by cutting a couple traces and adding some passive components.

3) I really need to sleep more. ;)

In addition, regarding the power supply, I highly recommend that the 152 not be modified. I do not believe it is safe to operate without the minimum load. There are 2 options. Create a load on the -12V rail, like I have shown with either a fan or a bulb, or you can also source an appropriately sized 1U ATX power supply and modify it using the instructions I have provided.


--
Brian
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

barcher174

Hi Rob,

I think it would be possible to create a switched approach to this mod. If you put a switch between "pin 2" on the ASIC and ground the soundbox should operate at 72hz again. Also you would want to leave the ADB trace in place. Other speakers will work with the board without a problem. Just try to match the impedance of the existing one.  For the power supply you want to pull the load from the output side. This means 12V DC power. Probably a cool thing to do would be to find a router with the right power threshold and make a cube add-on card out of it.

Rob Blessin Black Hole

Quote from: "barcher174"Hi Rob,

I think it would be possible to create a switched approach to this mod. If you put a switch between "pin 2" on the ASIC and ground the soundbox should operate at 72hz again. Also you would want to leave the ADB trace in place. Other speakers will work with the board without a problem. Just try to match the impedance of the existing one.  For the power supply you want to pull the load from the output side. This means 12V DC power. Probably a cool thing to do would be to find a router with the right power threshold and make a cube add-on card out of it.

I think I'll try this for fun .. I found a 4 pin molex connector to 12volt dc on EBay and I have a molex power splitter
To split power off from the molex connector on the cube power supply that normally supplies the 2 internal drives , I have a lynksys wireless 54g router , that I'm going to flash upgrade to ddwrt software then set it up as an ethernetbridge ....
It fits nicely in the cube case and run an rj 45 cable from internal cube router to the 68040 motherboard , Wireless cube lol.
....
Question , can an atx power supply power 2 motherboards .... The mod you did is very cool so I'm guessing it has enough juice to power up the cube board and a dimension but it would be cool if it was moded to power up a small form factor intel motherboard or perhaps a mac mini kind of like an original stock cube with a hemi in it as well varooom a few more cooling fans a cherry on top an internal Apple TV as well .
I guess the 983 power supply has more juice so maybe there is a way to power up an internal Mac mini and original motherboard lol mad science.
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

gtnicol

It should be very easy to hook the video output up to a VGA to create a complete VGA adapter. Very cool.

I must say I'm surprised though because the ASIC on the non-ADB boards multiplex sound, keyboard etc. onto the 5MHz bus. I'm wondering now what versions of the OS might work with this.

gtnicol

Ahhhh. Looks like the ASIC kept the non-ADB logic in it, rather than being re-programmed for ADB (which is what I had assumed) Very cool! My understanding of the ASIC pinout is something like this:


     4 3 2 1 28 27 26
     _________________
    /                |
5  |                 | 25
6  |                 | 24
7  |                 | 23
8  |                 | 22
9  |                 | 21
10  |                 | 20
11  |                 | 19
    +--------------------------------+
    12 13 14 15 16 17 18

1 sound in data
2 sound in sync
3 reset
4 power +5V
5 ground
6 5MHz clock
7 5MHz serial in
8 5MHz serial out
9 keyboard out
10 keyboard in
11 ground
12 power +5v
13 ?
14 ? DAC data
15 ? DAC clock
16 ? DAC select
17 oscillator
18 power +5v
19 ground
20 mute
21 volume control ?
22 volume data
23 volume clock
24 ?
25 ground
26 power +5v
27 ?
28 sound clock


So based on your picture, it looks like you're wiring the keyboard back onto the ASIC, which is then multiplexing back to the computer.... which is why this works. This should be compatible with older OS's too.

With a swap of the keyboard connector, and an adapter for the video out, we can have a nice VGA solution for older mono machines. Sweet!

barcher174

Hi Gavin

Yes that is all correct. The host OS has no idea about the board revision.

--
Brian

gtnicol

I guess with just a little imagination, we could also tweak the board to support ADB or non-ADB connectors. This is great news all around because the non-ADB boards are getting scarce, while ADB are plentiful.

barcher174

Yes, I think between you and Rob we have more ADB sound boards than next enthusiasts at the moment. I'm thinking maybe a 3D printable enclosure that would have VGA and a switch between ADB and non-ADB would be cool. I've been working on this for a good long while so I'm really happy to finally have results.

--
Brian

Rob Blessin Black Hole

Quote from: "barcher174"Yes, I think between you and Rob we have more ADB sound boards than next enthusiasts at the moment. I'm thinking maybe a 3D printable enclosure that would have VGA and a switch between ADB and non-ADB would be cool. I've been working on this for a good long while so I'm really happy to finally have results.

--
Brian


Yes, the NeXT ADB soundboards I have are one in the same  ... so I'm thinking I'll be able to offer a do it your self kit as I have new old stock external soundbox shells, faceplates, logos and internal mounting bracket for speaker and new old stock ADB sound board ... and I have the non adb keyboard connectors needed to make the conversion ...

I think around $30 complete kit less speaker and microphone or 2 for $50 and ~ $6 to $10 shipping probably $30 international would be reasonable,

or if someone just wants the New ADB soundboard $15 with non adb connector for conversion .  

Once I have the soundboard conversion template and make a few locally I can factor in a nominal labor cost for a ready to go modded non adb soundbox or combo adb / non adb , if needed .

Also along with this thread link a youtube step by step demo will help the DIY crew!

And a couple buck discount for Forum members would be in order.

I personally paid $99 and $139 for  non adb soundboxes recently on ebay and flipped for cost to fill orders for customers so this is a nice pricebreak,  we can offer for everyone .

I also have the custom Y cables needed to hook up to flat panels for $65 .  I like the custom Y cable as it allows the monitor to be separated from the soundbox  but I'm positive a functional pass through will be cooland save a few dollars  .

The best part is all of the old NeXT's we can now revive ; this is fun for me!  I was going to show our attempts last year at figuring this conversion out for comedy, we successfully soldered the connectors to the boards and they powered up but we lacked the knowledge of cutting traces and soldering to the asics and Brian thank you once more !   I'm throwing in a couple NeXT goodies for your kudos prize!

Gavin do you recall having / seeing a box of original speakers or microphones for the unassembled soundboxes  in the cache I picked up from you.... I've found hidden gems at the bottoms of some boxes still a few dozen more to go through !

Best Regards Rob Blessin

:roll:
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

barcher174

I did a test fit inside a sound box today.

First image shows how I installed the keyboard connector upside down. I put electrical tape underneath to insulate the previous connections and then glued the connector in place.

https://www.dropbox.com/s/h8p3w46wetr68ge/IMG_0582.JPG

And here it is in a sound box:

https://www.dropbox.com/s/vv94y2s6al06ydc/IMG_0581.JPG

Here I've annotated the connections on an unmodified board:

https://www.dropbox.com/s/tchizz8d1kvoxnk/IMG_0588.JPG

A closer look at the ASIC:

Unmodified:
https://www.dropbox.com/s/eajs0jlpbdzg6bq/IMG_0585.JPG

Modified:
https://www.dropbox.com/s/zijahhjo7hvgq5u/IMG_0584.JPG

I also updated the PDF instructions here:

https://www.dropbox.com/s/g27eqfy08oq06pz/Next%20ADB%20Convertion.pdf

--
Brian

Rob Blessin Black Hole

Brian Ahh yes the lightbulb went on when I realized from your annotations that the blue VGA connector on the board is where the CRT in a 4000a or 4000b connects for video so .... I'm guessing this is where the pass through cable to VGA would connect to a flatpanel. If that is the case , I'm wondering is the 152 power supplies would perceive it as load and just work because the video signal is passing through the connector.
On a mono slab with monitor video passes through it  and not around it with a color slab  ycable , I know a color slab hooked to a mono monitor won't display video probably because the video signal is rgb and routed around it using the 13w3 connector.
Hunch ...We just need to match the soundboard pin outs on the on board VGA connector then reroute them to a VGA adaptor to display 2bit gray scale. I may have a doa 4000a shell and a flat panel that will fit in it. How cool would it be to use that pass through in an original NeXT monitor shell with original sound card plenty of room for rockin speakers or a wireless router and a flat panel display.... I'll check to see if the flat panel fits in the shell .  
I tried synching a view sonic 15" v150 b using a non adb soundbox and the custom cable on a monoturbo , it shows a usable 2 bit Image and is off centering OSD won't adjust . It has a small enough foot print to fit in the shell, next test is a nice sony 17" fp searching for the power connector lol.
I just had this thought for color on a slab but using the 4000a shell with frog design stand you have the sound card and speaker , mount the flatpanel 1280 by 1024 synche on green connect a 13w3 to VGA adaptor to your y cable .... That would look cool .....


Quote from: "barcher174"I did a test fit inside a sound box today.

First image shows how I installed the keyboard connector upside down. I put electrical tape underneath to insulate the previous connections and then glued the connector in place.

https://www.dropbox.com/s/h8p3w46wetr68ge/IMG_0582.JPG

And here it is in a sound box:

https://www.dropbox.com/s/vv94y2s6al06ydc/IMG_0581.JPG

Here I've annotated the connections on an unmodified board:

https://www.dropbox.com/s/tchizz8d1kvoxnk/IMG_0588.JPG

A closer look at the ASIC:

Unmodified:
https://www.dropbox.com/s/eajs0jlpbdzg6bq/IMG_0585.JPG

Modified:
https://www.dropbox.com/s/zijahhjo7hvgq5u/IMG_0584.JPG

--
Brian
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

barcher174

Hi All,

Good news. Since I have additional boards coming in the mail I decided to experiment on my personal ADB soundbox. Non-ADB and ADB can live happily together in a single sound box. No switch necessary. Just wire the signals as I've already shown and leave the ADB connection uncut. You will of course need to cut a hole in the enclosure to support a second connection, but there is plenty of room inside. Seems like we've got this one solved.

--
Brian

Rob Blessin Black Hole

Quote from: "barcher174"Hi All,

Good news. Since I have additional boards coming in the mail I decided to experiment on my personal ADB soundbox. Non-ADB and ADB can live happily together in a single sound box. No switch necessary. Just wire the signals as I've already shown and leave the ADB connection uncut. You will of course need to cut a hole in the enclosure to support a second connection, but there is plenty of room inside. Seems like we've got this one solved.

--
Brian

Awesome that is great news as I think combo sound boxes will resolve chasing down the right model sound box , keeps the original board intact and minimizes the modding ; I'm ready to improve my solder skills  l Any recommendations on wire or type of solder. I'm guessing flipping the non adb keyboard connector and glue or Velcro  it to the top of adb keyboard connector and drilling a hole in the back of the soundbox shell should work.
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93