Modern Soundbox Replacement

drakar · December 05, 2018, 01:39:44 PM

I've been working on this for quite a while and finally have a working prototype to show:

Yep, that's a soundbox made out of modern parts! Ignore the wires, they're just breaking out all of the connections for testing.
It handles ADB and non-ADB keyboards for whatever the system can support (ADB systems are happy to use non-ADB hardware) and will convert mono video to VGA. It also deals with the sound protocol (though there's no sound output... yet) so as far as the system is concerned the sound works fine and the system test passes.

So far I've tested it on mono and color slabs, a turbo color using non-ADB and ADB, and a cube.

I still need to write up the protocol details and will post those later.

nuss · December 05, 2018, 02:16:00 PM

A very interesting & cool project, I like it!
Please keep up your good work

barcher174 · December 05, 2018, 03:22:04 PM

Awesome! How did you handle the synchronous UART? Bit banging?

drakar · December 05, 2018, 04:48:53 PM

I'm using an FPGA to handle the communication. It's a really different approach than what I was used to but is super powerful and can easily handle the high speed data.

krazycat · December 09, 2018, 02:11:47 PM

Awesome project! keep us informed of progress

Rob Blessin Black Hole · December 10, 2018, 03:00:23 AM

It also deals with the sound protocol (though there's no sound output... yet) so as far as the system is concerned the sound works fine and the system test passes.

>>>>> Would it be possible to add powered speakers and powered microphone / headphone jacks ? I know with the regular sound cards you can by pass the internal speaker and micro phone plugging into the ports .

Amazing work , would it also be possible to add a switch for USB KB/ MS Support in emulation
as this amazing widget may be able to bypass the proprietary NeXT Sound Box , Keyboard and Mice Interface which for me would be huge as I have a ton of original NeXT Motherboards , power supplies and floppies.... in Theory a Custom NeXTStation Slab Case could be 3d printed or current case slightly modded where that fits under the hood and on cubes it mounts to a filler slat. We have the new capacitors , and Version 5.1 PCB's ....... just need the vampire over the 68040 / fpga reality distrortionater to kick it all into high gear or the Cube Intel Expansion board.
The I860 Intel Chips on the Dimensions were highly programmable, I wonder if any of the NeXT engineers tinkered with designing a Pentium Expansion board for the Cube .... as the NeXTstep 486 Pentium , HPPA Risc and Sparc software breakout ports shut down the hardware production path that was going towards Risc , they could have in theory made one more motherboard upgrade for Cube owners Intel or may be we still can.... especially taking a gander at what they are doing modding the retro Amiga side ..... we shall see.

drakar · December 10, 2018, 08:39:06 AM

Sound is possible but much more complicated, I'm working on one that has a speaker and headphone jack.
It should be possible to add USB as well, the only problem with adding all of these features is that it gets bigger and costs more. Maybe I'll do a mega-deluxe version with everything on it and a smaller kb-only version.

gtnicol · December 10, 2018, 08:54:32 AM

Quote from: "barcher174"Awesome! How did you handle the synchronous UART? Bit banging?

In my hacking, I was bit-banging with a fast microprocessor. Shame to have a CPU that can emulate the main machine doing that...

zombie · December 10, 2018, 03:19:23 PM

Quote from: "Rob Blessin Black Hole"It also deals with the sound protocol (though there's no sound output... yet) so as far as the system is concerned the sound works fine and the system test passes.

>>>>> Would it be possible to add powered speakers and powered microphone / headphone jacks ? I know with the regular sound cards you can by pass the internal speaker and micro phone plugging into the ports .

Amazing work , would it also be possible to add a switch for USB KB/ MS Support in emulation
as this amazing widget may be able to bypass the proprietary NeXT Sound Box , Keyboard and Mice Interface which for me would be huge as I have a ton of original NeXT Motherboards , power supplies and floppies.... in Theory a Custom NeXTStation Slab Case could be 3d printed or current case slightly modded where that fits under the hood and on cubes it mounts to a filler slat. We have the new capacitors , and Version 5.1 PCB's ....... just need the vampire over the 68040 / fpga reality distrortionater to kick it all into high gear or the Cube Intel Expansion board.
The I860 Intel Chips on the Dimensions were highly programmable, I wonder if any of the NeXT engineers tinkered with designing a Pentium Expansion board for the Cube .... as the NeXTstep 486 Pentium , HPPA Risc and Sparc software breakout ports shut down the hardware production path that was going towards Risc , they could have in theory made one more motherboard upgrade for Cube owners Intel or may be we still can.... especially taking a gander at what they are doing modding the retro Amiga side ..... we shall see.

So this is an interesting and somewhat related project. Someone took all the circuitry of an original Mac Plus and pulled it all in so it could be downloaded to an FPGA:

https://www.bigmessowires.com/2015/10/22/plus-too-mac-replica-new-progress/

I would imagine we might be able to eventually do the same thing for NeXT hardware. Dump it all down into a single FPGA.

Oh yea, and Kudos! This is such a great project!

drakar · February 08, 2019, 12:53:49 PM

Here they are! I have a small first batch available now: NeXTBox at Drakware

Still working on a version with sound, but that'll take some time and will be bigger and cost a bit more.

So far I've tested with mono, color, and color turbo stations, as well as a cube. It won't work with a 152 power supply (unless you have a dummy load on it) but 983 is fine.

krazycat · February 08, 2019, 01:55:53 PM

Hi Matt, do you plan to sell this card even without the external case?

drakar · February 08, 2019, 03:35:43 PM

Sure, I can sell them without it. It'd be nice to make one that fits in your 3d printed soundbox shell but the connectors wouldn't line up, and PCB-mount DB19 connectors went extinct long ago. Could probably make an odd-shaped PCB that would fit around a panel mount DB19 though, if you're aiming to make a full-on replica.

barcher174 · February 09, 2019, 02:52:49 PM

How did you fake the sound test? Is the DAC pin bidirectional?

drakar · February 09, 2019, 03:23:49 PM

The sound output is serial data that comes from the system on pin 4 of the DB19 cable, so this sends the appropriate responses on pin 5 but doesn't actually use the sound data for anything.

barcher174 · February 09, 2019, 03:32:17 PM

Do you know what the ASIC is looking for to generate that response though? The DAC level communication.