dr.zeissler wrote on 2025-11-23, 07:51:

That would be the ultimate sound solution for my PS/2E and you can put me on the first buyers list if this comes out. Thx!

Thank you. Not sure if the device will be for sale anywhere (at least not by me), but all the required files will be publicly available, meaning that anyone would be able to build it and I would not hesitate to have the device available through a store (if they contact me).
Anyway, really cool machine, it would make me happy to see it upgraded with this device.

DarcTangent wrote on 2025-11-22, 23:24:

Wow, awesome project! I'd love to see ESS AudioDrive support for ESFM capability in Windows like the Micro Solutions backpack LPT CD-ROM drives. It would be incredible to add DOS support like the OPLxLPT family for the ESS chips (DOS TSR). CD-ROM emulation would be cool too. I look forward to seeing how this project grows. Cheers!

We'll see what will be possible for this device. As I have already mentioned, it is in its early stages of development, therefore I cannot guarantee anything as of now. The main goal is to implement sound devices mentioned in the original post. Then we can try to build on top of it.

digger wrote on 2025-11-22, 07:56:

Thanks for the update!

As with any newly designed product, you will likely be able to iteratively improve the design in later revisions.

Glad you found a possible combination to allow for software-controlled mode-switching. Having a batch file for each game to set the ideal mode will be much more convenient than having to manually toggle between modes with a button on the device, depending on what game you want to play or what application you want to run.

Yes, after some thinking I came up with another enhancement. Since the data lines on LPT port should preferably be bidirectional for better support of other devices (such as some sort of WiFi adapter, storage device etc.), I consider using three different chips for LLC, apart from the ones already mentioned, also the SN74LVC8T245 which is bidirectional and would suit the project really well. The main problem is that this chip is not sold (at least as far as I know) in a DIP package; therefore, I need to design PCB with SMD components in mind. So DIY assembly won’t be as easy as I had hoped.

Nice,

That is something I wanted to do if I had more time (and not the PicoMEM/PicoCPC/Other project in progress 😀

With a MicroSD, you can even plan for ZIP drive, Parallel port Wifi, MIDI ? support.

FreddyV wrote on 2025-11-25, 17:10:

Nice,

That is something I wanted to do if I had more time (and not the PicoMEM/PicoCPC/Other project in progress 😀

Hmmm... "Other project"? Curious to learn more about that, once you have something to reveal about it. 😁

With a MicroSD, you can even plan for ZIP drive, Parallel port Wifi, MIDI ? support.

All cool ideas, although MIDI is probably better handled through the serial port with something like the MPU-232, right? That has the added advantage of MIDI and digital working side by side in an easy way, with music over serial and PCM through the parallel port.

Perhaps at some point in the future, a later revision of this device could be improved so that it plugs into both a parallel port and a serial port (and optionally perhaps the PS/2 mouse/keyboard port available on many laptops as well), and then allowing it to support a lot more stuff for older laptops and PS/2 computers, such as USB keyboard and mice, USB joysticks and game controllers, MIDI over serial, plus all the parallel port devices it can emulate.

But maybe that's best to do in a separate project to prevent scope creep.

MIDI on LPT is actually possible.

My PCB based on eigenco's LPT2MIDI.

https://github.com/eigenco/LPT2MIDI

but this design still had some issues, like missing notes
i bet this is because the port is split and arduino code is not optimal.

matze79 wrote on 2025-11-26, 09:35:

MIDI on LPT is actually possible.

I'm aware that it's possible. I know of such projects.

It just makes more sense to me to do MIDI over serial, so the parallel port stays free for PCM output.

With very few exceptions (such as certain Tandy 1000 models), pretty much any non-ISA PC or laptop that has a parallel port also has a serial port anyway.

From what I've understood, the MIDI interface is basically a serial interface already, just with a bit rate that PC serial ports don't support. And devices such as the MPU-232 offer solutions for that.

But yeah, I have no objections to adding MIDI functionality to the Picovox over the parallel port. The more flexibility, the better, of course. 🙂

I guess it might be useful when the serial port is already in use for something else, such as a serial mouse.

FreddyV wrote on 2025-11-25, 17:10:

Nice,

That is something I wanted to do if I had more time (and not the PicoMEM/PicoCPC/Other project in progress 😀

With a MicroSD, you can even plan for ZIP drive, Parallel port Wifi, MIDI ? support.

Not really sure about the MIDI support, I don't think that even Pico 2 is powerful enough for any meaningful MIDI sound production. It would totally be possible to add a MIDI output port but the question is whether that is really needed since you can do it via serial port. But LPT WiFi and some mass-storage media (whether ZIP drive or something else) were on my mind for quite some time already. Also, adding an SD-card reader would make it possible to store and easily modify some configuration, such as the default simulated device, volume levels and even stored WiFi credentials. All these ideas I had already been thinking about were also the reason I decided to use a bidirectional LLC instead of a unidirectional one.

digger wrote on 2025-11-26, 09:04:

Hmmm... "Other project"? Curious to learn more about that, once you have something to reveal about it. :grin: […]
Show full quote

FreddyV wrote on 2025-11-25, 17:10:

Nice,

That is something I wanted to do if I had more time (and not the PicoMEM/PicoCPC/Other project in progress 😀

Hmmm... "Other project"? Curious to learn more about that, once you have something to reveal about it. 😁

With a MicroSD, you can even plan for ZIP drive, Parallel port Wifi, MIDI ? support.

All cool ideas, although MIDI is probably better handled through the serial port with something like the MPU-232, right? That has the added advantage of MIDI and digital working side by side in an easy way, with music over serial and PCM through the parallel port.

Perhaps at some point in the future, a later revision of this device could be improved so that it plugs into both a parallel port and a serial port (and optionally perhaps the PS/2 mouse/keyboard port available on many laptops as well), and then allowing it to support a lot more stuff for older laptops and PS/2 computers, such as USB keyboard and mice, USB joysticks and game controllers, MIDI over serial, plus all the parallel port devices it can emulate.

But maybe that's best to do in a separate project to prevent scope creep.

Pretty much sums up all my thoughts. Extension of the project for multiple ports seems a bit far-fetched. I don't think that one device should occupy all your ports, especially if their function would be almost completely unrelated. Probably the only good reason for this approach would be to power the device from PS/2's 5V supply instead of an external microUSB power brick (still I would like to add two holes for a jumper where you can provide any 5V input). I think that it is totally reasonable to make another device connecting Pico to the COM port and adding support for different standards there.

digger wrote on 2025-11-26, 09:58:

I'm aware that it's possible. I know of such projects. […]
Show full quote

matze79 wrote on 2025-11-26, 09:35:

MIDI on LPT is actually possible.

I'm aware that it's possible. I know of such projects.

It just makes more sense to me to do MIDI over serial, so the parallel port stays free for PCM output.

With very few exceptions (such as certain Tandy 1000 models), pretty much any non-ISA PC or laptop that has a parallel port also has a serial port anyway.

From what I've understood, the MIDI interface is basically a serial interface already, just with a bit rate that PC serial ports don't support. And devices such as the MPU-232 offer solutions for that.

But yeah, I have no objections to adding MIDI functionality to the Picovox over the parallel port. The more flexibility, the better, of course. 🙂

I guess it might be useful when the serial port is already in use for something else, such as a serial mouse.

Yeah most Laptops only have one, so you have to decide.
That was my reason also for LPT MIDI Adapter.

If this really gets into shape, it would be nice to make a all in one tsr with some sort of communication do get the plug auto switch the devicetype maybe by issue a command from cmd.

Any news on this project? Do you need some help testing, @jansakos?

I can try soldering one together based on your initially shared designs, if that helps.

Anybody else here willing to contribute to the project as well? Thanks.

It’s not so much about testing right now, the main problem is that there isn’t enough time for the project itself. But don't worry, it's not abandoned, I am running some tests with improved filtering of the 3.3 V rail and also some sketches for the PCB. Here’s a quick overview: I have decided to go with three different chips for LLC, one for 3.3V -> 5V, one for 5V -> 3.3V and one for 3.3V <-> 5V (switchable). With this approach the device shall be able to simulate both SPP and PS/2 mode (bi-directional), and possibly additional advanced modes for higher speeds. Also, I have decided to connect each pin of the LPT to the Pico so that you aren’t limited and can use every pin. I will try to order the first prototype of the PCB and if it all works (I hope it will), I will share all the files for the PCB itself. As for the source code, it works reasonably well at the moment (the same version I provided in my earlier post), but I want to add TNDLPT and CMSLPT support and clean up the code before releasing it publicly. You are free to build the provided prototype, but I am experiencing trouble with noise and I hope I have found a solution to that.

@jansakos Hackaday published an article yesterday about level-shifting.

It mentions verious approaches, and also links to a YouTube video.

Could some of that be useful for this project, maybe? 🙂