I'm just blown away by how good that sounds considering it's just a bunch of resistors! I was expecting something only marginally better than the PC speaker, but that's not the case at all. I can totally see why people without sound cards were constructing these back in the day :)
@@xys007 Most DOS games used 8-bit samples anyway at 11025 Hz (or lower) sampling frequency, so it's not like there's a big hit in sound quality, which wasn't there to begin with.
Really for sample rate under 16khz or so, the added benefit of more bits is limited... I would say maybe 10. But a lot of those bits is mostly use for volume or dynamic range that is less of a factor in 90s games
Building this Sound Bastard just for the .MOD player alone was worth it. Very impressive for such a primitive device ! I'm considering making one myself, just for fun.
Yeah, for me it is so impressive, because of it's simplicity in the first place. You wouldn't expect such result from something like this :) It was funny to make, furthermore, I got some practice in EDA, as I wanted and needed for another project I'm working on. And last, but not least, I have an IBM PS/2 machine to restore. It has only MCA slots and I have no sound option for it, so the Sound Bastard will come quite handy there :)
Was expecting you to try Doom haha, but this is pretty great. Some of the filtered audio from the music player at the beginning was very nostalgic. Nice!
Unfortunately Doom will not work with this. The sound blaster emulator works only in real mode games, so all the older ones, but Doom runs in protected mode.
I have to revise this statement. There is one open source fork of doom now available, which supports DACs on LPT, like Covox. See github.com/viti95/FastDoom
I use to build these back in the 80's. I also had one that had both the R2R DAC and an 8 bit ADC in the same small shell. 40Khz 8 bit mono sampling..on a printer port.
Hehe, thank you very much. This channel exists already since two years, it's just that I mostly made videos for myself until last month..... I will never understand, how YT works :)
I am an E.E i did not think it was possible as well till it was mentioned then i felt a pop in my brain and understanding was unleashed and it makes perfect sense now.
You could also place a trimmer pot in series with your tone caps. The cap will always control where the lowpass filter sits, but you can control how effective it is with the trimmer. It's pretty much an electric guitar's passive tone circuit, just with smaller parts.
I've watched this video a dozen times, and here I am again. I've made my own Covox inspired on your design (I already told you that in another video, though), and I use it to play MP3s with DSS under DOS. I'd love to see Mpxplay adding Covox support in the future...
Yes! I used to work at Covox! I worked at Dynamix too on a WW2 flight sim, and a skiing game. At Covox I only did solder repair on returned units. There was a HDD company in Eugene I worked at a bit too...Hsomething? It has been too long. I always get nostalgic when I see a Covox product. At some point there was an optional employee meeting after work, they gave us all a speach thing...or demo scene soundcard. I had a Sound Blaster card, so I gave it to a friend. Oh you just made me very nostalgic. The quality of Covox (build wise) was good compared to the price. I miss those days.
Hi Necro!!!! Every video is a little box of surprises... I am speechless... What a great idea to build a modded Covox... I love the elysium mod without filters :) but it is only my pref... Fantastic job!!!
Thank you Jorge! Glad you liked it :) Yeah, I think too, that it sounds the best in the recording, when unfiltered. But as I told, in the passive headphones it was too noisy and 100nF didn't make any difference at all. However, 1uF was just right and in the recording it sounds awful. I guess, it depends very much on the speakers, also if they are active or passive. That's why I made it switchable, just to make such experiments.
resistors must have been really expensive back in the 70s since IBM couldn afford to put 8 of them in the PC so it could output something decent instead of bips and bops
IBM was some serious business. I think even the idea that their computers could be used for entertainment was viewed as sinful, perverted and completely incompatable with the core values of the company. lol
Probably just opted not to include much sound capability. Keep in mind that most people were probably listening to records or maybe cassette tape back then. Also, since these have to be directly driven by software they probably eat a lot of CPU… Not that big a deal on a 486 or later, but the original IBM had an Intel 8088.
So weird, I knew about this for a long time (how easy it is to build a DAC with some resistors) but I never made one. I was an Amiga user and the parallel port was seldom used much for anything. I wished I made a cheap mixer with it so that it would cost nearly nothing and just add a fifth 8 bit channel mixed in both left and right. That would have been nice actually even for the Amiga 500 I think... Could have some drum and bass stuff in the "middle channel" fifth channel... And I know it was easy to software mix more channels then 4 hardware ones ofc.
yeah :) i'm an Amiga guy, and did a little bit of research in that regard. thing is: you can think of the speech thing as a reverse parallel port sampler. as you know, when sampling sound on your Amiga's built-in parallel-port, it becomes useless, your sampling software will freeze the Amiga. that's because the parallel-port, as opposed e.g. to the sound outputs, cannot be accessed by a custom chip (with DMA). parallel port it is handled by the CPU, thus high (usable) sampling rates, or playback rates on the speech thing, will pretty much halt the entire system. (the situation might be different on e.g. an A4000 with some parallel-port on a Zorro-card, i don't know.) so, long story short: speech thing and Amiga is super tempting, but doesn't go together too well. (sadly.) :) (PCMCIA port on A600/A1200 and 16-bit hi-fi speech thing is super tempting, too. :-D )
@@amigaalive6266 You have done the research and I have not used my Amigas for a long time (I did have 2 different samplers though). And yes that is true, sampling programs did not multitask (but I think they could) it was just badly non OS written software. And when sampling you did not want any task having more priority because then you could loose bytes. But for playback I think some form of interrupt (playing sounds i.e just putting bytes on the parrallellport lets say a 8 Khz equivalent sample on the parallel port for a game that has some leftover CPU time (adventure games, and stuff like that.. cutscenes on other games) would be doable... And ofc pure sound programs at least for the A1200 it would not be a problem I think even with higher sampling rates on parrallellport? or do you mean accessing the parallel port (in this case puting a byte on the datalines cuts the DMA off completely?) I do know the parallel port data needs to be handled by the CPU and has no DMA. But you can put samples anywhere in memory you can just not play it using DMA and Amiga custom chips. This sounds like something I would loved to do, but my Amiga 500 is a long way from where I live and my A1200 is in bits and both needs a recap. But it should not be impossible for interrupt driven routine to play samples (from either fast or chipmem) thru an simple D/A on the parallel port In my mind at least. I think you need to convince me some more to make this a really bad idea 🙂 The ultimate would also be do (as I said in my original post) a small mixer (analogue mixer) that you could also in the same case as the parallel D/A converter could just put you normal Amiga 4 channel (2 leads) cables and a couple of options or maybe just one... so the parallel port "channel" could be mono mixed into both stereo channels. If you understand how I mean?
@@alexanderwingeskog758 yes, totally :-) i'm not trying to convince you that it's a bad idea. more like the opposite. i just think there might be some serious limitations. but it is certainly possible. i wrote a workbench-compliant sampler program, and i think it kinda worked up to somewhere around 10khz or so. when switching off some stuff (multitasking & display, i think) i got a little more, around 15khz i think. so maybe as a rough estimation if you use the speech thing at maybe 5khz there might be enough bandwidth left to do something else meaningful with the computer.
Noise suppression - could we use optocouplers to help? I made one of these resistor network parallel port sound cards when I was a kid - it was so much fun.
Nice to see stereo Covox, I've been curious about that and other mono to stereo hardware transitions. Took a long time in retrospect for digital audio to reach the stereo standard.
Btw this DAC has no default output frequency. From the software side it's just as primitive as the circuit itself. You output a byte in a manual CPU directed way and it 'immediately' appears on the output. The real maximum sampling rate depends on the speed with which of the output operation gets through the ISA bus and the parallel port chips. So it can be theoretically the highest among the sound cards - problem is, it eats up the CPU as it has to be instructed to output every single byte "by hand" and it's usually done via a very high frequency timer interrupt. And it opens another can of worms. Because operations that can't be *immediately* interrupted they can and will cause immense jitter in the output signal so it won't ever be an audiophile device :D You'll surely hear a lot of crackling and other distortions whenever the computer does anything beyond playing the music and some simple tolerable things in the meantime...
@@necro_ware Just a demo of the dual parallel port setup where 25% of the left is mixed into the right, and 25% of the right mixed into the left so it's not as jarring on the ears. Things are rarely hard panned in audio for that reason. I mean if you still have the raw tracks you could just mix it in your audio program of choice. Would be fun to hear.
@@PJBonoVox Ah, ok, I understand now. This has nothing to do with a Covox itself, but with an external mixer, right? I'll try, when I have time, out of curiosity, but in the video it was my intention to show, that the channels are really separated :) However, this experiment would more fall into the category audio, then retro hardware, don't you think?
@@necro_ware No idea :) I was always annoyed with my Amiga and how the stereo separation was 100%. Terrible in headphones. Just would be cool if you built an adapter to allow you to mix the stereo. All good though, still love the content!
yes, in the recording indeed. But since this device has no amplifier, it sounds differently with various devices. With headphones the sound is the best with a strong filter.
While it is affected by the load, it's also because the sampling rate is really low. It depends on the output (mixing) rate of the player, and also the quality of the samples themselves -- which in a 4-ch MOD are usually pretty.. terrible. :-) The HF content you do hear isn't actually supposed to be there. The sampling process, when sampling at low 8kHz rates common for MOD samples, actually removes all the HF information, samples the remaining bits, then you're supposed to run it through a DAC with the same low-pass filter as the input. When you don't filter it, there's kind of a "mirror image" of the audio, with all the content BELOW the Nyquist frequency (1/2 sample rate) being mirrored ABOVE the Nyquist frequency. This is called aliasing, and it isn't supposed to be there. But since the sample rate is so low, there's no intended signal in the HF region, which sounds dull. So sometimes that aliasing noise makes it sound, subjectively, a little brighter and more interesting. A little bit, at least. Too much and it quickly gets fatiguing. It's distortion, and like all distortion, it's not _supposed_ to be there, but sometimes it's OK that it is. :-)
Why do those old mod files sound so much better here than they do when I play them in OpenMPT? It just sounds so much better with the speech bastard thing "degrading" the sound!
I don't know :D I left the links to the music in the description, you can use them to play the files directly in browser. You could compare the quality to your OpenMPT playback there...
I wonder if the data rate of a parallel port is good enough, along with sufficiently fast shift registers and a more custom output format not compatible with Covox, to give us 14-bit mono audio, like mono NICAM on British (and maybe other) TVs.
With the mono, low sample rate of DOS games from the SB era, a Covox (/clone) can actually sound pretty close to the real thing. There are a lot of caveats to that, though. Support being one of them. Variable output loads, another. High CPU usage and/or lots of jitter in the audio, since there's no sample buffer. etc. etc. Also, the SB wasn't a very high bar to begin with. :-) It was only slightly more sophisticated than the software-driven ladder DAC! It did have a sample buffer, and IRQ. But the sample playback was basically a microcontroller bit-banging samples to a cheap DAC, just barely better than the R2R. Hardly audiophile quality. haha Leagues better than the PC speaker, though! I wish I had understood all of this back in my early 386 days. I wanted a sound card _soooo_ bad, and could've easily had one with a quick trip to Radio Shack. I played MOD files through my PC speaker. A Covox clone would've been a huge improvement!
Makes me wonder about building one of these, but internal, and connecting to the small ribbon cable of a multi I/O device, such that there's just the audio jack sticking out of the back. Being internal, it could also have access to the power supply, and thus build in an amplifier. And I realize there would be little point, but I'm also wondering if you could make your own ISA card with a parallel controller but just wired up straight to this configuration, no 25-pin port existing at all.
It's actually very easy to make, you don't even need a parallel port controller, since you can simply setup the address per software and decode directly on the bus. I made a prototype of such card, but another tinkerer was faster and he made it even in stereo: www.retrokits.de/index.php/dual-isa-dac-r0-covox-speech-thing-on-isa-bus/
I'm really surprised that this didn't become THE standard for audio in the late 80s/early 90s. Parallel port was everywhere and simplicity of this device should've made it a no-brainer upgrade for the PC speaker and even compete with adlib for a fraction of the price.
It plays only digital sound. That takes a lot of memory, which was very expensive back then. Adlib on the other hand was FM sound playing notes and not digital samples. That needed significantly less memory and CPU power. That's why Adlib was more successful.
Just a by the way. The fake stereo you were talking about is actually called mirrored mono. It has its uses, especially when you're outputting stereo from a mono source, like radio broadcasting.
@@necro_ware Dual mono is another term for the same thing. Just putting this out there, I'm in no way trying to be mean or anything. I love the videos. I think it's awesome to see some hardware from my childhood live again. My goal is to help you since it appears English is not your first language
The Atari ST had some games like Wings of Death that gave you the option to use the printer port for sound, and it sounds better than the monitor speaker.
I need to make one of these! Had no idea about the Tandy 3-Voice emulation. What CPU would that require to work and give playable results in games? 8088 too slow? 286? 386? Might make a simpler one for myself with permanent "stereo" and a single 10-50nf cap for filtering , I thought even the 100 was a bit harsh. Other than that I'm loving it. Such a cool part of our history.
Yeah, for recording 100nF was a bit too much, but unfortunately I had nothing else between 1nF and 1µF at hand. And as I told, for my passive headphones 1µF was perfectly fine. If you are interested in something similar, but more sophisticated, then watch this th-cam.com/video/wW1th462IKM/w-d-xo.html With a transmitter, a DAC IC and an amplifier, the quality will be even better and you will have a much more stable output, I guess, so that the filters will not make such a big difference, when you take some different speakers. However, it is the simplicity of the solution I've chosen, what fascinates me so much. Regarding the Tandy emulation, unfortunately, it needs a 386. May be, there is a way to get it running on a 286 as well. However, since audio over a parallel port can't use any direct memory access (DMA), you will need all the processing power you can get and an 8088 or 286 would be just not enough anyway. I tested it on a 386SX-25 and there it was running ok. In some games you could feel a slowdown, when a sound was played. It's a nice thing for experiments and learning about the tech, but as I told in the video, If your primary aim is to play games, probably an Adlib or SB-Compatible is a better solution. Especially, if you think, that the most games back in the days were written for OPL2/3 and not for digital sound.
I used to make these myself, loads of resistors and solder, then throw it all in a LPT housing, testing it and filling it with silicone so it wouldn't move/break hahah... oh man the memories, must have been like 1992/1993...
For the Sound Blaster emulator messing with the computer's clock means that it has to do something with the computer's clock (well duh). That clock in DOS runs at 18.2Hz and DOS' time is based on this. It's a general purpose clock, and it actually has multiple "channels", one of which is connected to the PC-Speaker. What the emulator is doing is probably messing with it for something (maybe to generate an interrupt on each tick and output sound ?). I wonder if it this can be made differently, maybe that alone could fix the bugs you witnessed ?
I didn't look into the code yet. VSB was made by the same guys as TEMU AFAIK and the source is openly available. I'll have to find some time to look into, however, I guess it is full of implications and hacks, so it is probably not quite easy to understand. If you are interested: github.com/volkertb/temu-vsb
I did this experiment 1988 with my MSX2 computer. With 1 row of resistors. At that time there weren't that many sound cards only the Philips music module, but those were no longer available or very expensive. Nice experiment, I thought the soundquality sounded tinny and too digital. Later came the FM Pac, and years later the soundcard to be for the MSX2> computers by moonsoft the OPL4 card "moonsound"
You can do it with one row of resistors, but it's really hard, because they have to be very precise to get the right proportion. Else the sound quality will be very bad. It is much easier to make it with 3 rows of resistors of same value. This way even cheap resistors will sound ok'ish.
Covox and Disney Sound Source were totally different devices. Sound Source was fixed to 7 kHz (by design!), but it also had small FIFO buffer. It made huge difference in performance. CPU had to send data to Covox in constant intervals at very high rate, while Disney Sound Source had circuitry to play samples on it's own from FIFO buffer. So CPU could transfer data at much lower intervals in bursts. Digitized samples were CPU heavy on it's own in early PC days, but Covox was even more taxing on the hardware. Even though it was very popular device especially in demo scene, games rarely used it. The problem was simple, early DOS games didn't use digitized samples. Tandy, Adlib and MT32 didn't had such feature. This is why Disney Sound Source and Covox were rarely used by games. With time cheap Sound Blaster clones dominated the market and DOS games rarely supported Covox, despite using sound middleware with drivers for tons of devices. On the other hand there are Windows drivers for Covox, which increases significantly software library with all Windows 9x games.
Person who reverse engineered the Disney Sound Source and built a compatible circuit here. The DSS wasn't exactly capable of playing samples on it's own, the buffer is basically implemented to prevent buffer overflows/underruns - if the software supports it. Afterall the buffers are tiny ... 8 byte if I'm not mistaken (has been a while since I worked on it). In fact if you set the playback rate to 7KHz a covox would even be less CPU consuming, as it's a "fire and forget" type device while the DSS needs constant attention to the buffer in most cases - games by Apogee very likely just constantly streamed empty data, even when there was nothing to play back. While the DSS design made sense for very low end systems, it barely made sense in the 486 era. One major benefit of the DSS over the Covox is that it can be autodetected in software.
Hi there! Thank you very much for your support, but are you sure that wasn't a mistake? Please don't get me wrong, I really appreciate the help, it is really huge, but I don't make this channel professionally and I'm always worried about such big donations.
@@necro_ware no mistake - as said before, I owe this era of hardware my life. I wouldn’t be where I am today so please enjoy it and keep the videos coming :)
thanks for this video I didnt realize all the options with these devices. Im thinking i might put one together to improve pc speaker games (if they support tandy sound)
You are welcome! As I told all the schematics are open hardware and you can use them if you want. Another user @HeavyD6600 also made a Silly Sound Bastard for himself based on my plans. You can watch some videos about it on his channel. He makes a nice review and even speaks more in detail about the assembly. See: th-cam.com/channels/795052gCeYosTs1_fODjkA.html
Covox was very popular in ex-USSR at early '90. And was present patcher known as covoxer, that enables support in many games, even stereo DAC on single LPT port (IC based, idr which one, it was in dip24, dont mention variants on cheaper 572ПА1 aka AD7520)
One solution to avoid switching capacitors would be to use an op amp on the card, so the value needed doesn't depend of what is pluggued. And eventually with an active low pass filter. But not sure it's worth :)
Yeah, definitely, it would be a lot better to have an amp. But just as I told in the video, I wanted to have it passive and as simple as possible. Unfortunately, a parallel port doesn't supply any power, so I'd need an external power supply then, which I didn't want. However, if I'd make it active, beside an amp, I'd also use a bus transceiver and a DAC as IC and not as bunch of resistors. Something like this: th-cam.com/video/wW1th462IKM/w-d-xo.html
@@necro_ware Every digital signal provides power. ;-) You just have to harvest it. You would need a very low-power op-amp willing to run with a single supply at low voltage. But thanks to mobile electronics, that isn't too hard to source.
@@nickwallette6201 Sure, this was how serial mice did work. They pulled their power directly from the digital signals. But with parallel port you are somewhere around handful of mA, if you pull from all registers. I prefer not to burn my parallel port and I know couple of people, who already did ;) They said, that they will need only 10mA, well, was a bad idea.
@@necro_ware An important point. However, it depends on what you use, I think. I just did a quick search on Digikey for LV audio or general-purpose single-channel op-amps with supply current less than 2mA, and found (just picked one at random) the Rohm BU7485G. Typical current is 1.5mA, max 2.0mA. That ought to be 100% safe to phantom-power from a couple diode-isolated port status pins or something. And there are lower-power options still - down to nA! Of course there are also some that consume tens or low hundreds of mA, without considering output load even, so choose carefully. :-) IMO, a buffered line-level output could be done in a way that should be compatible with any parallel port. After all, driving headphones from the DAC output can consume a few mA as well. ;-) And there are those troubleshooting devices with pass-through ports and LEDs to show activity on the pins.. those would have to be pulling at least 1mA, from any pin at logic high. Anyway, just my 2c. :-)
I built one of these in early 90s , i little bit uglier than the examples you shown LoL , and i recall the first music i listened.. Enjoy the Silence , nice memories :)
As if I didn't have enough projects on my bench already. Now I just GOTTA make myself a Silly Sound Bastard! I've got a Tandy 1100FD that could use it. No 3-voice chip on that one.
Stereo gefriemelt, das gibt einen Daumen nach oben.
ปีที่แล้ว
Would it be possible to re-use one of the other IEEE1284 / parallel port pins (next to the data pins) to gain another data output pin, boosting from 8 bit sound to 9 or 10 bit sound? e.g. nSelect-Printer or Linefeed
I actually didn't plan to. Well I have two PCBs left over, but I didn't think about it. I think it depends. Where do you live? If the delivery costs are higher, than the price, it is probably cheaper for you to order the PCBs using my gerber files, which I opened in GitHub. On the other hand, if you just want to support my channel ;)
I didn't try it on a XT, but I guess, to some degree, you could. At least, playing music at 8kHz sampling rate could work. However, without DMA, all the work of data transfer has to be done by CPU and for a 8086 it could be just too much. Furthermore, the tools I've shown to emulate Tandy sound and Sound Blaster, need at least 386 CPU. Still, just out of curiosity, I'd give it a try :) You can find all the gerber files to order the PCBs in the repository from the description, but for an experiment, you can solder something yourself, or even use breadboard. Just to see if it works.
I don't see a use case yet, but may be you can. As far as I know, at least in Windows 95 there was a Covox Speech Thing driver and may be it survived up to Windows 10? I suppose not, but who knows?! And if you use some old DOS program from the command line in Windows 10, probably it will be able to access LPT and use the Covox Speech Thing (clone) directly. I don't have windows 10 here however, so I can't check it.
@@necro_ware My big project I have been working on has lots of 8 bit Arduinos and one Mega 2560. I just need to generate noise and maybe a little music to mix into a sound board to give it a little robotic sound. I have found that a modified version of Josh Levine code for his video "Build a giant scrolling LED text display for about $15 per foot" worked sort of. It annoyingly speeds up as the loop runs its course. Link to my project: th-cam.com/video/NCm6vHOR6uY/w-d-xo.html
One would think that pc games creators would push this to make games sound better. Im also pretty sure there was drivers for windows 3.1.. making it way more usable.
Just thinking out of the box here, would it be possible to make a "dual module" that plugs into 2 LPT ports and output 16 bit mono sound (8 bits from each port). How would you combine them?
I think, it should be possible, but you would have to write your own software to use it. I didn't heard about such approach yet. I think, that stereo was more important, than 16-bit samples. However, nobody said, that you can't use 4 DACs on LPT1 to LPT4 and make a stereo 16-bit setup :)
Ok, its impressive! But why u didnt print a new card with all the components which u need instead of 2 card, u worked hard in this project but i think u can make it absolutly perfect
Because for the solution with two LPT ports you need two cards. It is possible to make stereo on one LPT port using one card, but that is a completely different design, more complicated and with active components. My point was actually to show how simple and though impressive it can be.
For a dedicated stereo MOD file playing machine It would be neat to build an ISA card with the two parallel controllers onboard along with the resistor ladders and other assorted circuitry. It would be very niche though.
I've never seen sound cards running in SLI before.
Hehe, true :)
i did
This is more of a CrossFire to me :D
No, just no. That's not how it works. It's two similar devices working in tandem.
@@forevercomputing If SLI stands for Scan Line Interleave so there may be something like - for example - ACI - Audio Channel Interleave ;-)
1990: i want a Sound Blaster
2021: i want a Silly Sound Bastard
I'm just blown away by how good that sounds considering it's just a bunch of resistors! I was expecting something only marginally better than the PC speaker, but that's not the case at all. I can totally see why people without sound cards were constructing these back in the day :)
Bear in mind that this is only 8 bit sound.
@@xys007 Most DOS games used 8-bit samples anyway at 11025 Hz (or lower) sampling frequency, so it's not like there's a big hit in sound quality, which wasn't there to begin with.
It’s a R-2R ladder DAC, just built out of discrete components.
Really for sample rate under 16khz or so, the added benefit of more bits is limited... I would say maybe 10. But a lot of those bits is mostly use for volume or dynamic range that is less of a factor in 90s games
Wow, what a cool project and great video. 100x thumbs up 👍🏻. Thank you for sharing this with the community.
Building this Sound Bastard just for the .MOD player alone was worth it. Very impressive for such a primitive device !
I'm considering making one myself, just for fun.
Yeah, for me it is so impressive, because of it's simplicity in the first place. You wouldn't expect such result from something like this :) It was funny to make, furthermore, I got some practice in EDA, as I wanted and needed for another project I'm working on. And last, but not least, I have an IBM PS/2 machine to restore. It has only MCA slots and I have no sound option for it, so the Sound Bastard will come quite handy there :)
I think "silly sound bastard" is the best product name... almost ever.
Wait untill ultra silly soundblaster comes.
Was expecting you to try Doom haha, but this is pretty great. Some of the filtered audio from the music player at the beginning was very nostalgic. Nice!
Unfortunately Doom will not work with this. The sound blaster emulator works only in real mode games, so all the older ones, but Doom runs in protected mode.
@@necro_ware Ahhhh, makes sense! :)
I have to revise this statement. There is one open source fork of doom now available, which supports DACs on LPT, like Covox. See github.com/viti95/FastDoom
I use to build these back in the 80's. I also had one that had both the R2R DAC and an 8 bit ADC in the same small shell. 40Khz 8 bit mono sampling..on a printer port.
Great to see a fresh new player in the retro computing scene. I'm really enjoying the approach for the videos. Keep it up !!
Hehe, thank you very much. This channel exists already since two years, it's just that I mostly made videos for myself until last month..... I will never understand, how YT works :)
That is so cool! I had no idea you could make a DAC using only resistors! Crazy.
I am an E.E i did not think it was possible as well till it was mentioned then i felt a pop in my brain and understanding was unleashed and it makes perfect sense now.
DAC is resistors
there is support logic and what not, but DAC itself is extremely accurate resistors and nothing more
You could also place a trimmer pot in series with your tone caps. The cap will always control where the lowpass filter sits, but you can control how effective it is with the trimmer. It's pretty much an electric guitar's passive tone circuit, just with smaller parts.
Never knew this was a thing, awesome and informative video, thank you! Also that intro on your later videos rock :D
I grew up with ibm computers all the way back from xt and have never heard of this before now
I've watched this video a dozen times, and here I am again. I've made my own Covox inspired on your design (I already told you that in another video, though), and I use it to play MP3s with DSS under DOS. I'd love to see Mpxplay adding Covox support in the future...
Yes! I used to work at Covox! I worked at Dynamix too on a WW2 flight sim, and a skiing game.
At Covox I only did solder repair on returned units.
There was a HDD company in Eugene I worked at a bit too...Hsomething? It has been too long. I always get nostalgic when I see a Covox product. At some point there was an optional employee meeting after work, they gave us all a speach thing...or demo scene soundcard. I had a Sound Blaster card, so I gave it to a friend.
Oh you just made me very nostalgic. The quality of Covox (build wise) was good compared to the price. I miss those days.
Yes, I love this simple device too, it wakes up a lot of nostalgic feelings in me as well.
@@necro_ware 😁
I wish I had more than one like to give. Great video, and I'm looking forward to doing this.
I still have these same MOD files on my hard drive. They have been migrating to each new computer since the early 90s.
Same here, although nowadays they are on a network share.
I will definetly be building some of these in the near future. This is so cool
I love seeing a resurgence of interest in these!
That is so cool, I especially liked the stereo section. well constructed and presented
Hi Necro!!!! Every video is a little box of surprises... I am speechless... What a great idea to build a modded Covox... I love the elysium mod without filters :) but it is only my pref... Fantastic job!!!
Thank you Jorge! Glad you liked it :) Yeah, I think too, that it sounds the best in the recording, when unfiltered. But as I told, in the passive headphones it was too noisy and 100nF didn't make any difference at all. However, 1uF was just right and in the recording it sounds awful. I guess, it depends very much on the speakers, also if they are active or passive. That's why I made it switchable, just to make such experiments.
I still have mine from the early 90s made on Radio Shack perf board. Used it to play mods. Great times! Brought some fun to boring PCs!
Just excellent
What a damned good video sir, I had only read about this as a kid, seeing it in real life with proper explanations is a real treat
That's genius! If I had known that, I would have asked a friend to solder it for me back then.
I believe the later Covox Sound Master cards implemented the same resistor ladder DAC as a hybrid module.
Brilliant! That reminds me of the Proatracker tracks I used to listen to on my Amiga
resistors must have been really expensive back in the 70s since IBM couldn afford to put 8 of them in the PC so it could output something decent instead of bips and bops
or maybe IBM appointed some CEOs in Creative Labs, allegedly, lol, stranger things have happened
Nobody expect at this time IBM PC will be used as a game computer, so no need to offer sound better that a beep to acknowledge user action...
IBM was some serious business. I think even the idea that their computers could be used for entertainment was viewed as sinful, perverted and completely incompatable with the core values of the company. lol
Probably just opted not to include much sound capability.
Keep in mind that most people were probably listening to records or maybe cassette tape back then.
Also, since these have to be directly driven by software they probably eat a lot of CPU… Not that big a deal on a 486 or later, but the original IBM had an Intel 8088.
just amazing how good this simple circuit emulate the real audio card
Emulate nothing, it *IS* the real audio card! :D
Module music - that what inspire me to start study programming. Even now I am impressed how good Impulse Tracker can play music through pc speaker …
Nice memories, I still have an LPT - audio converter at home, with a time when sound cards were extremely expensive and inaccessible
Yes, as I told in the video, unfortunately I don't have my anymore, which I built 30 years ago....
very interesting with a fist of resistance you make your sound card !!! I think I'm starting to build one too ...... or two :)
So weird, I knew about this for a long time (how easy it is to build a DAC with some resistors) but I never made one. I was an Amiga user and the parallel port was seldom used much for anything. I wished I made a cheap mixer with it so that it would cost nearly nothing and just add a fifth 8 bit channel mixed in both left and right. That would have been nice actually even for the Amiga 500 I think... Could have some drum and bass stuff in the "middle channel" fifth channel...
And I know it was easy to software mix more channels then 4 hardware ones ofc.
yeah :) i'm an Amiga guy, and did a little bit of research in that regard. thing is: you can think of the speech thing as a reverse parallel port sampler. as you know, when sampling sound on your Amiga's built-in parallel-port, it becomes useless, your sampling software will freeze the Amiga. that's because the parallel-port, as opposed e.g. to the sound outputs, cannot be accessed by a custom chip (with DMA). parallel port it is handled by the CPU, thus high (usable) sampling rates, or playback rates on the speech thing, will pretty much halt the entire system. (the situation might be different on e.g. an A4000 with some parallel-port on a Zorro-card, i don't know.) so, long story short: speech thing and Amiga is super tempting, but doesn't go together too well. (sadly.) :) (PCMCIA port on A600/A1200 and 16-bit hi-fi speech thing is super tempting, too. :-D )
@@amigaalive6266 You have done the research and I have not used my Amigas for a long time (I did have 2 different samplers though). And yes that is true, sampling programs did not multitask (but I think they could) it was just badly non OS written software. And when sampling you did not want any task having more priority because then you could loose bytes. But for playback I think some form of interrupt (playing sounds i.e just putting bytes on the parrallellport lets say a 8 Khz equivalent sample on the parallel port for a game that has some leftover CPU time (adventure games, and stuff like that.. cutscenes on other games) would be doable... And ofc pure sound programs at least for the A1200 it would not be a problem I think even with higher sampling rates on parrallellport? or do you mean accessing the parallel port (in this case puting a byte on the datalines cuts the DMA off completely?)
I do know the parallel port data needs to be handled by the CPU and has no DMA. But you can put samples anywhere in memory you can just not play it using DMA and Amiga custom chips.
This sounds like something I would loved to do, but my Amiga 500 is a long way from where I live and my A1200 is in bits and both needs a recap.
But it should not be impossible for interrupt driven routine to play samples (from either fast or chipmem) thru an simple D/A on the parallel port In my mind at least.
I think you need to convince me some more to make this a really bad idea 🙂
The ultimate would also be do (as I said in my original post) a small mixer (analogue mixer) that you could also in the same case as the parallel D/A converter could just put you normal Amiga 4 channel (2 leads) cables and a couple of options or maybe just one... so the parallel port "channel" could be mono mixed into both stereo channels. If you understand how I mean?
@@alexanderwingeskog758 yes, totally :-) i'm not trying to convince you that it's a bad idea. more like the opposite. i just think there might be some serious limitations. but it is certainly possible. i wrote a workbench-compliant sampler program, and i think it kinda worked up to somewhere around 10khz or so. when switching off some stuff (multitasking & display, i think) i got a little more, around 15khz i think. so maybe as a rough estimation if you use the speech thing at maybe 5khz there might be enough bandwidth left to do something else meaningful with the computer.
Noise suppression - could we use optocouplers to help? I made one of these resistor network parallel port sound cards when I was a kid - it was so much fun.
Nice to see stereo Covox, I've been curious about that and other mono to stereo hardware transitions. Took a long time in retrospect for digital audio to reach the stereo standard.
“Silly Sound Bastard” Tickled me every time you said it! 😂🇬🇧
Some of the Sound Effects sounded pretty good through my Surround Sound System to be fair! 🙂
This is awesome! I wonder if you can take a standard digital signal and run it through an R2R with success?
Btw this DAC has no default output frequency. From the software side it's just as primitive as the circuit itself. You output a byte in a manual CPU directed way and it 'immediately' appears on the output. The real maximum sampling rate depends on the speed with which of the output operation gets through the ISA bus and the parallel port chips. So it can be theoretically the highest among the sound cards - problem is, it eats up the CPU as it has to be instructed to output every single byte "by hand" and it's usually done via a very high frequency timer interrupt. And it opens another can of worms. Because operations that can't be *immediately* interrupted they can and will cause immense jitter in the output signal so it won't ever be an audiophile device :D You'll surely hear a lot of crackling and other distortions whenever the computer does anything beyond playing the music and some simple tolerable things in the meantime...
It should be far superior to the PC speaker though which is afaik similarly driven.
@@jnharton From my experience, it is.
It'd be great if in the future we could see another demo where you mix the two stereo signals with a kind of 50% stereo spread or something.
I guess, I don't understand yet. Could you explain a bit more, what you mean?
@@necro_ware Just a demo of the dual parallel port setup where 25% of the left is mixed into the right, and 25% of the right mixed into the left so it's not as jarring on the ears. Things are rarely hard panned in audio for that reason.
I mean if you still have the raw tracks you could just mix it in your audio program of choice. Would be fun to hear.
@@PJBonoVox Ah, ok, I understand now. This has nothing to do with a Covox itself, but with an external mixer, right? I'll try, when I have time, out of curiosity, but in the video it was my intention to show, that the channels are really separated :) However, this experiment would more fall into the category audio, then retro hardware, don't you think?
@@necro_ware No idea :) I was always annoyed with my Amiga and how the stereo separation was 100%. Terrible in headphones. Just would be cool if you built an adapter to allow you to mix the stereo. All good though, still love the content!
Ok, thank you for the feedback. I'll see if I can embed it somehow in another video, in case I get it working. Cheers!
No filtering sounds the best. With the 100nF it sounds muddy.
yes, in the recording indeed. But since this device has no amplifier, it sounds differently with various devices. With headphones the sound is the best with a strong filter.
@@necro_ware oh okay 👌 I thought it might be something like that.
While it is affected by the load, it's also because the sampling rate is really low. It depends on the output (mixing) rate of the player, and also the quality of the samples themselves -- which in a 4-ch MOD are usually pretty.. terrible. :-) The HF content you do hear isn't actually supposed to be there. The sampling process, when sampling at low 8kHz rates common for MOD samples, actually removes all the HF information, samples the remaining bits, then you're supposed to run it through a DAC with the same low-pass filter as the input.
When you don't filter it, there's kind of a "mirror image" of the audio, with all the content BELOW the Nyquist frequency (1/2 sample rate) being mirrored ABOVE the Nyquist frequency. This is called aliasing, and it isn't supposed to be there. But since the sample rate is so low, there's no intended signal in the HF region, which sounds dull. So sometimes that aliasing noise makes it sound, subjectively, a little brighter and more interesting. A little bit, at least. Too much and it quickly gets fatiguing.
It's distortion, and like all distortion, it's not _supposed_ to be there, but sometimes it's OK that it is. :-)
that is so cool. when you said the sound was not good what did you mean?? it sounds great.
Why do those old mod files sound so much better here than they do when I play them in OpenMPT? It just sounds so much better with the speech bastard thing "degrading" the sound!
I don't know :D I left the links to the music in the description, you can use them to play the files directly in browser. You could compare the quality to your OpenMPT playback there...
I wonder if the data rate of a parallel port is good enough, along with sufficiently fast shift registers and a more custom output format not compatible with Covox, to give us 14-bit mono audio, like mono NICAM on British (and maybe other) TVs.
I enjoyed building myself one of these, back in the day. Then upgraded to dual Sound Blasters. ;)
With the mono, low sample rate of DOS games from the SB era, a Covox (/clone) can actually sound pretty close to the real thing. There are a lot of caveats to that, though. Support being one of them. Variable output loads, another. High CPU usage and/or lots of jitter in the audio, since there's no sample buffer. etc. etc.
Also, the SB wasn't a very high bar to begin with. :-) It was only slightly more sophisticated than the software-driven ladder DAC! It did have a sample buffer, and IRQ. But the sample playback was basically a microcontroller bit-banging samples to a cheap DAC, just barely better than the R2R. Hardly audiophile quality. haha Leagues better than the PC speaker, though!
I wish I had understood all of this back in my early 386 days. I wanted a sound card _soooo_ bad, and could've easily had one with a quick trip to Radio Shack. I played MOD files through my PC speaker. A Covox clone would've been a huge improvement!
Makes me wonder about building one of these, but internal, and connecting to the small ribbon cable of a multi I/O device, such that there's just the audio jack sticking out of the back. Being internal, it could also have access to the power supply, and thus build in an amplifier.
And I realize there would be little point, but I'm also wondering if you could make your own ISA card with a parallel controller but just wired up straight to this configuration, no 25-pin port existing at all.
It's actually very easy to make, you don't even need a parallel port controller, since you can simply setup the address per software and decode directly on the bus. I made a prototype of such card, but another tinkerer was faster and he made it even in stereo: www.retrokits.de/index.php/dual-isa-dac-r0-covox-speech-thing-on-isa-bus/
I'm really surprised that this didn't become THE standard for audio in the late 80s/early 90s. Parallel port was everywhere and simplicity of this device should've made it a no-brainer upgrade for the PC speaker and even compete with adlib for a fraction of the price.
It plays only digital sound. That takes a lot of memory, which was very expensive back then. Adlib on the other hand was FM sound playing notes and not digital samples. That needed significantly less memory and CPU power. That's why Adlib was more successful.
Sound coming straight out the printer port is funny
Covox in stereo! Excellent hack!
Wonder if you could do surround with it
Just a by the way. The fake stereo you were talking about is actually called mirrored mono. It has its uses, especially when you're outputting stereo from a mono source, like radio broadcasting.
Yes, true. I also heard dual mono or something similar, but may be that was in another language. I mix sometimes the terms.
@@necro_ware Dual mono is another term for the same thing.
Just putting this out there, I'm in no way trying to be mean or anything. I love the videos. I think it's awesome to see some hardware from my childhood live again. My goal is to help you since it appears English is not your first language
@@thomasvlaskampiii6850 Everything's fine :D I appreciate every constructive help and you are not mean at all. Thank you very much.
The Atari ST had some games like Wings of Death that gave you the option to use the printer port for sound, and it sounds better than the monitor speaker.
I need to make one of these! Had no idea about the Tandy 3-Voice emulation. What CPU would that require to work and give playable results in games? 8088 too slow? 286? 386?
Might make a simpler one for myself with permanent "stereo" and a single 10-50nf cap for filtering , I thought even the 100 was a bit harsh. Other than that I'm loving it. Such a cool part of our history.
Yeah, for recording 100nF was a bit too much, but unfortunately I had nothing else between 1nF and 1µF at hand. And as I told, for my passive headphones 1µF was perfectly fine. If you are interested in something similar, but more sophisticated, then watch this th-cam.com/video/wW1th462IKM/w-d-xo.html
With a transmitter, a DAC IC and an amplifier, the quality will be even better and you will have a much more stable output, I guess, so that the filters will not make such a big difference, when you take some different speakers. However, it is the simplicity of the solution I've chosen, what fascinates me so much.
Regarding the Tandy emulation, unfortunately, it needs a 386. May be, there is a way to get it running on a 286 as well. However, since audio over a parallel port can't use any direct memory access (DMA), you will need all the processing power you can get and an 8088 or 286 would be just not enough anyway. I tested it on a 386SX-25 and there it was running ok. In some games you could feel a slowdown, when a sound was played. It's a nice thing for experiments and learning about the tech, but as I told in the video, If your primary aim is to play games, probably an Adlib or SB-Compatible is a better solution. Especially, if you think, that the most games back in the days were written for OPL2/3 and not for digital sound.
I used to make these myself, loads of resistors and solder, then throw it all in a LPT housing, testing it and filling it with silicone so it wouldn't move/break hahah... oh man the memories, must have been like 1992/1993...
Hi!
Amazing project! Do you have BOM/CPL files?
I'm not so good to assemble boards:(
I will try to buy assembled.
For the Sound Blaster emulator messing with the computer's clock means that it has to do something with the computer's clock (well duh).
That clock in DOS runs at 18.2Hz and DOS' time is based on this. It's a general purpose clock, and it actually has multiple "channels", one of which is connected to the PC-Speaker. What the emulator is doing is probably messing with it for something (maybe to generate an interrupt on each tick and output sound ?). I wonder if it this can be made differently, maybe that alone could fix the bugs you witnessed ?
I didn't look into the code yet. VSB was made by the same guys as TEMU AFAIK and the source is openly available. I'll have to find some time to look into, however, I guess it is full of implications and hacks, so it is probably not quite easy to understand. If you are interested: github.com/volkertb/temu-vsb
since this help folks understand how dac/s works...imagine you can built entire external sound card by adding more chips
I did this experiment 1988 with my MSX2 computer.
With 1 row of resistors. At that time there weren't that many sound cards only the Philips music module, but those were no longer available or very expensive.
Nice experiment, I thought the soundquality sounded tinny and too digital.
Later came the FM Pac, and years later the soundcard to be for the MSX2> computers by moonsoft the OPL4 card "moonsound"
You can do it with one row of resistors, but it's really hard, because they have to be very precise to get the right proportion. Else the sound quality will be very bad. It is much easier to make it with 3 rows of resistors of same value. This way even cheap resistors will sound ok'ish.
Covox and Disney Sound Source were totally different devices. Sound Source was fixed to 7 kHz (by design!), but it also had small FIFO buffer.
It made huge difference in performance. CPU had to send data to Covox in constant intervals at very high rate, while Disney Sound Source had circuitry to play samples on it's own from FIFO buffer. So CPU could transfer data at much lower intervals in bursts.
Digitized samples were CPU heavy on it's own in early PC days, but Covox was even more taxing on the hardware. Even though it was very popular device especially in demo scene, games rarely used it.
The problem was simple, early DOS games didn't use digitized samples. Tandy, Adlib and MT32 didn't had such feature. This is why Disney Sound Source and Covox were rarely used by games.
With time cheap Sound Blaster clones dominated the market and DOS games rarely supported Covox, despite using sound middleware with drivers for tons of devices.
On the other hand there are Windows drivers for Covox, which increases significantly software library with all Windows 9x games.
Person who reverse engineered the Disney Sound Source and built a compatible circuit here. The DSS wasn't exactly capable of playing samples on it's own, the buffer is basically implemented to prevent buffer overflows/underruns - if the software supports it. Afterall the buffers are tiny ... 8 byte if I'm not mistaken (has been a while since I worked on it). In fact if you set the playback rate to 7KHz a covox would even be less CPU consuming, as it's a "fire and forget" type device while the DSS needs constant attention to the buffer in most cases - games by Apogee very likely just constantly streamed empty data, even when there was nothing to play back. While the DSS design made sense for very low end systems, it barely made sense in the 486 era. One major benefit of the DSS over the Covox is that it can be autodetected in software.
Jester/Sanity, oh yeah, that Amiga vibe ;)
bloody impressive mate.
I had a Disney Sound Source, but your version is way better. Love the music - might put this together myself - donation incoming :)
Hi there! Thank you very much for your support, but are you sure that wasn't a mistake? Please don't get me wrong, I really appreciate the help, it is really huge, but I don't make this channel professionally and I'm always worried about such big donations.
@@necro_ware no mistake - as said before, I owe this era of hardware my life. I wouldn’t be where I am today so please enjoy it and keep the videos coming :)
How did you get the cool grey theme on MFED? mine seems to be the default blue/white - thanks!
Wouldn't there be a way like to add a switch or something to improve compatibility with Disney Sound Source?
Not so simple, DSS needs some active elements, a buffer and a clock.
I can't believe it sounds like this. I thought it will be way worse..
I remember seeing the option for covox in games and thinking how bad it must be
This is actually closer to the disney sound source than the covox. although the disney didn't have filtering
Not really. DSS had a buffer clocked at 7kHz, this is just a simple DAC, what Covox basically is.
I was dragged here by the author.in chains. Not disappointed though. Good name for a project too lmao!
:) haha... in chains
thanks for this video I didnt realize all the options with these devices. Im thinking i might put one together to improve pc speaker games (if they support tandy sound)
You are welcome! As I told all the schematics are open hardware and you can use them if you want. Another user @HeavyD6600 also made a Silly Sound Bastard for himself based on my plans. You can watch some videos about it on his channel. He makes a nice review and even speaks more in detail about the assembly. See: th-cam.com/channels/795052gCeYosTs1_fODjkA.html
It's like a very early form of digital amp! More like digital sound source but you know what I mean. Turning 1's and zeros to analog waveform
Covox was very popular in ex-USSR at early '90. And was present patcher known as covoxer, that enables support in many games, even stereo DAC on single LPT port (IC based, idr which one, it was in dip24, dont mention variants on cheaper 572ПА1 aka AD7520)
What you did wasn't "fake stereo" but in fact dual mono, two channels with the same signal.
One solution to avoid switching capacitors would be to use an op amp on the card, so the value needed doesn't depend of what is pluggued.
And eventually with an active low pass filter.
But not sure it's worth :)
Yeah, definitely, it would be a lot better to have an amp. But just as I told in the video, I wanted to have it passive and as simple as possible. Unfortunately, a parallel port doesn't supply any power, so I'd need an external power supply then, which I didn't want. However, if I'd make it active, beside an amp, I'd also use a bus transceiver and a DAC as IC and not as bunch of resistors. Something like this: th-cam.com/video/wW1th462IKM/w-d-xo.html
@@necro_ware Every digital signal provides power. ;-) You just have to harvest it. You would need a very low-power op-amp willing to run with a single supply at low voltage. But thanks to mobile electronics, that isn't too hard to source.
@@nickwallette6201 Sure, this was how serial mice did work. They pulled their power directly from the digital signals. But with parallel port you are somewhere around handful of mA, if you pull from all registers. I prefer not to burn my parallel port and I know couple of people, who already did ;) They said, that they will need only 10mA, well, was a bad idea.
@@necro_ware An important point. However, it depends on what you use, I think. I just did a quick search on Digikey for LV audio or general-purpose single-channel op-amps with supply current less than 2mA, and found (just picked one at random) the Rohm BU7485G. Typical current is 1.5mA, max 2.0mA. That ought to be 100% safe to phantom-power from a couple diode-isolated port status pins or something. And there are lower-power options still - down to nA! Of course there are also some that consume tens or low hundreds of mA, without considering output load even, so choose carefully. :-)
IMO, a buffered line-level output could be done in a way that should be compatible with any parallel port. After all, driving headphones from the DAC output can consume a few mA as well. ;-) And there are those troubleshooting devices with pass-through ports and LEDs to show activity on the pins.. those would have to be pulling at least 1mA, from any pin at logic high.
Anyway, just my 2c. :-)
Resistors in scematics dont line up with the connector drives my inner Monk mad! X_X
Just purchased one of these off you. Hoping it will work on an old dell laptop whos sound card isn't supported in dos other than as a pc speaker.
I built one of these in early 90s , i little bit uglier than the examples you shown LoL , and i recall the first music i listened.. Enjoy the Silence , nice memories :)
As if I didn't have enough projects on my bench already. Now I just GOTTA make myself a Silly Sound Bastard! I've got a Tandy 1100FD that could use it. No 3-voice chip on that one.
Yes, I know how it is :D I also have 1000s of projects running....
Stereo gefriemelt, das gibt einen Daumen nach oben.
Would it be possible to re-use one of the other IEEE1284 / parallel port pins (next to the data pins) to gain another data output pin, boosting from 8 bit sound to 9 or 10 bit sound? e.g. nSelect-Printer or Linefeed
I guess so, but you'd have no software, which would support it.
This is really cool!
Noob question: Is there any specific reason why tantalum caps are used for filtering as opposed to ceramic caps?
They have higher capacity, being just as small.
@@necro_ware Ah, I see! :) By the way I ordered five SSB long version PCBs earlier today. Thank you for making the design freely available!
Do you sell the pcb in europe?
I actually didn't plan to. Well I have two PCBs left over, but I didn't think about it. I think it depends. Where do you live? If the delivery costs are higher, than the price, it is probably cheaper for you to order the PCBs using my gerber files, which I opened in GitHub. On the other hand, if you just want to support my channel ;)
this was quite impressive !.. you got me subscribe today !... well done !
This is awesome! Wonder if I could make something like this work on my Sharp PC-7100 :-)
I didn't try it on a XT, but I guess, to some degree, you could. At least, playing music at 8kHz sampling rate could work. However, without DMA, all the work of data transfer has to be done by CPU and for a 8086 it could be just too much. Furthermore, the tools I've shown to emulate Tandy sound and Sound Blaster, need at least 386 CPU. Still, just out of curiosity, I'd give it a try :) You can find all the gerber files to order the PCBs in the repository from the description, but for an experiment, you can solder something yourself, or even use breadboard. Just to see if it works.
Where you've been when I saved money for sound card!!
Is there any way to do this in Windows 10? I have a LPT port on my motherboard.
I don't see a use case yet, but may be you can. As far as I know, at least in Windows 95 there was a Covox Speech Thing driver and may be it survived up to Windows 10? I suppose not, but who knows?! And if you use some old DOS program from the command line in Windows 10, probably it will be able to access LPT and use the Covox Speech Thing (clone) directly. I don't have windows 10 here however, so I can't check it.
@@necro_ware My big project I have been working on has lots of 8 bit Arduinos and one Mega 2560. I just need to generate noise and maybe a little music to mix into a sound board to give it a little robotic sound. I have found that a modified version of Josh Levine code for his video "Build a giant scrolling LED text display for about $15 per foot" worked sort of. It annoyingly speeds up as the loop runs its course. Link to my project:
th-cam.com/video/NCm6vHOR6uY/w-d-xo.html
Dood that's nuts!
Me watching this on my cellphone discovering it has true stereo builtin.
LOL :D It just needed an old covox to be unleashed.
very interesting video, never heard about this utility's
Can you use the port as a printer try to print Something? just to listen to what it gives :)
It's just noise, similar to a dial-in modem :D
Brilliant!
Amiga never dies!
The company? :p
One would think that pc games creators would push this to make games sound better.
Im also pretty sure there was drivers for windows 3.1.. making it way more usable.
Just thinking out of the box here, would it be possible to make a "dual module" that plugs into 2 LPT ports and output 16 bit mono sound (8 bits from each port). How would you combine them?
I think, it should be possible, but you would have to write your own software to use it. I didn't heard about such approach yet. I think, that stereo was more important, than 16-bit samples. However, nobody said, that you can't use 4 DACs on LPT1 to LPT4 and make a stereo 16-bit setup :)
Seems to work fine, still need to figure out the driver but I successfully played mod music and got Pinball Dreamsl 2 to work :D
This is excellent!
Ok, its impressive! But why u didnt print a new card with all the components which u need instead of 2 card, u worked hard in this project but i think u can make it absolutly
perfect
Because for the solution with two LPT ports you need two cards. It is possible to make stereo on one LPT port using one card, but that is a completely different design, more complicated and with active components. My point was actually to show how simple and though impressive it can be.
For a dedicated stereo MOD file playing machine It would be neat to build an ISA card with the two parallel controllers onboard along with the resistor ladders and other assorted circuitry. It would be very niche though.
If you have the luxury of access to software source code, you could probably build a more sophisticated external device without too much effort.
Has been done.
Check "Dual ISA DAC r1 - Covox Speech Thing on ISA Bus" by retroianer.
@@1337Shockwav3 Thanks!
You are Awesome!
Awesome!
whats that cad software your using?
For this project I was using EasyEDA, because I wanted to evaluate it. Usually I'm using KiCad.
@@necro_ware are they still availible?
@@TheMadmagik You mean EasyEDA? Yes, they belong to JLCPCB. Just google the name.