It's correctly configured.

Yup, looks fine. Sorry then, no idea what's wrong.
Maybe other forum members do have any idea what to do ? My knowlegde about Win98 isn't as in-depth as of them.
If this was about Win 3.x or XP, I'd probably recommend you to use Standard Mode instead or to install porttalk.
Even for OS/2 I could have given you a little tip here and there. But Win98..

squareguy wrote:

That is one of the coolest things I have seen in a long while. I was really surprised by the sound!

And it gets even better! 😁 There's a little TSR driver which can provide Tandy 3-voice and Sound Source support.
So you can enjoy these catchy tunes on your self-made Covox plug. Sound quality is nice for what it is.

Here's a sample for you. It was made with my old laptop along with a sluttishly made Covox clone.
The quality isn't the best, since my DAC only uses an approximation of what should be the proper resistor values.
The driver is also attached, since it is small and free.

Have fun!

(PS: I know this is old news for some of you.
I think there already was a discussion about this years ago. But I hope you don't mind nevertheless.)

I just read the article about Covox on Nerdly Pleasures http://nerdlypleasures.blogspot.com/2014/09/t … nd-devices.html
Man, if Covox was a little smarter and included the YM-3812 and a Gameport in their Sound Master card (1989), Creative would have been doomed.
But luckily for Creative Covox were sleep walking, so Creative took the opportunity with their killer card.

The Speech Thing sounds not half as bad, and it was released in 1986!, that's almost 4 years before the sound blaster.

Sounds GREAT!

The best part is that the DAC is essentially a fill-in-the-blanks element. The OP is a simple resistor ladder. You could spice it up with an op-amp for more linear response, substitute sigma-delta, etc. All from your own workshop.

Doc, I tried Inertia Player v1.21 and GLX v2.12 on my Compaq Armada.
It seems they do their own protected-mode magic that's incompatible with Windows.
Windows 98SE even displays a warning and asks you if you wish to run them in "MS-DOS mode".

The 16bit version of GLX (glx.exe) did work fine, though.
For some reason, it tried to access drive A: and gave an error message:

Not ready reading drive A
Abort, Retry, Fail?

It loaded fine, after I selected "F" for Fail. Playing music also worked via Sound Blaster Pro (and in a window).
However, playback via Covox did not work. I got sound, but the VU meter was dancing in slow-motion
and listening to the music wasn't very pleasant (see/hear recording in the attachment).
I'm speaking under correction, but I guess GLX tries to use the PC timer or interrupts for its own timing.
As we know, this doesn't work very well within Windows.

Jo22 thanks for sharing that Tandy TSR, I had no idea this thing existed! Sounds great!

The guys at Winhistory-Forum think, that glx with covox and win95 (before wdm) will work.
I have not tested this yet.

Inspired by this thread, I decided to add a Speech Thing and a PC Speaker recording of Pinball Fantasies to my recent Gravis Ultrasound recording comparison article : http://nerdlypleasures.blogspot.com/2016/10/r … ultrasound.html

My impression is that although the Speech Thing is quiet and in mono, the quality of the playback beats the SB Pro.

Just out of curiosity, would the Covox Speech Thing be at all appropriate for an IBM 5150 with a 7.16Mhz 286 upgrade and EGA graphics? On the list of Covox\Disney supported games on Mobygames, I see that they are all from '89 or '90 and later... which I'm thinking is pushing it for such an old system, but I have been curious about getting better sound quality without having to add a sound card (all expansion slots are full).

I'd love to build one of these, but it looks like PC games just didn't get much sound support until '89, which would have been much later than what this system is meant for. I'd still like to build a Covox-clone (and I plan to do a CMS upgrade from my CT1350B some time soon)... I'm just trying to figure out if there's any hope for a slow 286 with EGA graphics and 640k RAM.

@GH

To me the Speech Thing sounds like the PC speaker but with added lowpass filtering, both have some kind of distortion on top of the audible music.
I don't agree about ST sounds better than SBPro, it is much more distorted as already said.
As an audio hobbyist I don't equate more Treble as better sounding, although most people will.

Maybe you should do another recording with the SBPro filter Off to have another reference.
The Epic Pinball recording is with the Filter Off which is not the default, but Pinball Fantasies is with the filter On.

Some programs like MPXPlay and Doom will leave the mixer with Filter Off after exit and all games that don't reset or alter the mixer parameters will be affected.
Therefor the mixer program SBP-SET.EXE is always handy nearby when using a SBPro to reset or enable/disable the filter.
Or SBPVOL which is an excellent alternative I use.

I made myself one of those resistor ladder DAC cards about a year ago. It is a fun little project to do and sounds pretty good for what it is - sadly very few games support it natively and although that 3-voice TSR is amazing it only works in protected mode - so no use on PC/XT/AT machines. That means I don't use it regularly as most games in the 386-era used SB/OPL3. As I understand it the resistor DAC uses a lot of CPU time so that is why few games support it for in-game sound-effects. Star Control 2 is the only major title I can think of that actually supports it in-game. I'd love to know of other titles that do the same. It sounds great in iplay.exe although modules with many tracks start distorting. I used blue high-tolerance resistors to try to get the best possible sound - I've heard that that makes a difference.

I was so flushed with success after getting my resistor-ladder DAC to work that I tried making one from an actual chip DAC and an opamp. I copied the rough circuit posted some time back on this forum. I wasn't able to get it to work though. Sound was produced for maybe a second and then just a high-pitched whine. I must have either mis-read the diagram or messed up the circuit in some other way. The advantage of the DAC is that it's stereo, but iplay.exe is basically the only software I've seen that supports that. The proper DAC version also needs power though while the resistor one doesn't. One day I'll get the time to figure out what I did wrong.

Ozzuneoj wrote:

Just out of curiosity, would the Covox Speech Thing be at all appropriate for an IBM 5150 with a 7.16Mhz 286 upgrade and EGA graphics? On the list of Covox\Disney supported games on Mobygames, I see that they are all from '89 or '90 and later... which I'm thinking is pushing it for such an old system, but I have been curious about getting better sound quality without having to add a sound card (all expansion slots are full).

It should fit, I think. It was originally released circa '86, so it is a period-correct piece of hardware.
One of my favorite games, the Last-Half of Darkness, also supported the Covox DACs.
And the original release from '89 supported EGA graphics (withouth the "tendril plant" frame).
Maybe the "VGA graphics" version also still works in EGA mode (it did so in DOSBox).
Last Half of Darkness + Covox Speech Thing + DOSBox 0.73
http://www.mobygames.com/game/dos/last-half-o … ess/screenshots
http://playdosgamesonline.com/last-half-of-darkness.html

AnacreonZA wrote:

I made myself one of those resistor ladder DAC cards about a year ago. It is a fun little project to do and sounds pretty good for what it is - sadly very few games support it natively and although that 3-voice TSR is amazing it only works in protected mode - so no use on PC/XT/AT machines. That means I don't use it regularly as most games in the 386-era used SB/OPL3.

I see. I feel the same about native support. And I wished that TSR would also run on my 286s (I'm thankful it exists at all, nevertheless!)
Perhaps for technical reasons (DSS support ?) it was just not feasible to write such a neat thing in real-mode or 16bit protected-mode (see SoftMPU).
Or perhaps it simply started out as a programming excersie to learn about 80386 programming.. Who knows ?
But on the bright side, it doesn't need EMM386. So DOS itself isn't in V86 and so I can at least keep using my EMS card. ^^

AnacreonZA wrote:

As I understand it the resistor DAC uses a lot of CPU time so that is why few games support it for in-game sound-effects.

It depends. Sending pre-formatted PCM data (wave file) to an 8bit port might be less stressing for a PC than doing software-controlled PWM
(pulse-with-modulation) via PC-Speaker. The parallel port also has the advantage of having a buffer, an IRQ line and DMA support
(albeit Centronics in the 80s was a bit more limited). In some way or another, this is similar to the basics of a Sound Blaster card.
Speaking of Sound Blaster cards, the Aztech Sound Galaxy Pro 16 was one of the few cards which incorporated the functionality of a DSS/Covox DAC.
http://www.amoretro.de/2012/03/aztech-sound-g … axy-16-pro.html

AnacreonZA wrote:

Star Control 2 is the only major title I can think of that actually supports it in-game. I'd love to know of other titles that do the same. It sounds great in iplay.exe although modules with many tracks start distorting. I used blue high-tolerance resistors to try to get the best possible sound - I've heard that that makes a difference.

Star Control 2 looks interesting, it reminds me a bit of Star Flight..
I would also like to know about more titles with Speech Thing/Sound Source support. 😀
Yes, accurate resistors are important for good audio quality. However, for a first prototype you can use any types you like.

AnacreonZA wrote:

I was so flushed with success after getting my resistor-ladder DAC to work that I tried making one from an actual chip DAC and an opamp. I copied the rough circuit posted some time back on this forum. I wasn't able to get it to work though. Sound was produced for maybe a second and then just a high-pitched whine. I must have either mis-read the diagram or messed up the circuit in some other way. The advantage of the DAC is that it's stereo, but iplay.exe is basically the only software I've seen that supports that. The proper DAC version also needs power though while the resistor one doesn't. One day I'll get the time to figure out what I did wrong.

Sorry to hear, I wished I could help you. Unfortunatelly, this is difficult to do from the distance. 🙁
So I can only guess. Maybe your DAC has a different pinout (are you using the exact same from your schematic) ?
Or there's something wrong with the DAC's select line. Anyway, you can also give ModPlay Pro a try. It supports Stereo-on-1, too.
In theory, you could run even more DACs with it. Up to 4 (each for every MOD channel), I think.
It also has a little bit of free ASM space, where you can insert your own piece of code to support our own hardware.
But if nothing works, you can also build this one. It comes with a complete PCB layout.

@keropi No problem. You're welcome. ^^ @Doc I Haven't either. Maybe it works better on Win95.

James-F wrote:

@GH […]
Show full quote

@GH

To me the Speech Thing sounds like the PC speaker but with added lowpass filtering, both have some kind of distortion on top of the audible music.
I don't agree about ST sounds better than SBPro, it is much more distorted as already said.
As an audio hobbyist I don't equate more Treble as better sounding, although most people will.

Maybe you should do another recording with the SBPro filter Off to have another reference.
The Epic Pinball recording is with the Filter Off which is not the default, but Pinball Fantasies is with the filter On.

Some programs like MPXPlay and Doom will leave the mixer with Filter Off after exit and all games that don't reset or alter the mixer parameters will be affected.
Therefor the mixer program SBP-SET.EXE is always handy nearby when using a SBPro to reset or enable/disable the filter.
Or SBPVOL which is an excellent alternative I use.

I set my mixer settings to have the Output Filter Off with SBP-SET when I recorded Pinball Fantasies. I recorded them with the Filter On as well, but I did not notice any difference. The game may set the mixer itself, it does have an SB Pro driver setting.

What games would be enhanced by the Covox Speech Thing? I feel like it's too demanding in CPU power, and when correct CPU were around, so were proper sound card and games supporting them. Or was the Speech thing always meant as a low cost solution for people who can't get a proper sound card?

Speech Things were also useful for laptops of the early to mid 90s, which did not typically include any built-in sound hardware except for the PC speaker.

AnacreonZA, I just found something interesting and Covox related.. Perhaps this one is easier to build for you.
It's a Covox/Stereo-on-1 clone which uses some NAND-gates, an octal D-type latch, a PIC for the logic
and a Dual 16-bit DAC (TDA1543). Except for the DAC, this is common stuff.

It is described in Martin's 8-bit blog, which has some pretty ModPlay Pro pix.

Build a PC - soundcard second - Covox Stereo-on-1 (Martin's 8-bit blog)
http://www.8bity.cz/2014/postavte-si-pc-zvuko … ox-stereo-on-1/

The original page is in Czech, here's the translation into English.

Schematic, PCB layout and code can be found here.

Oh, and it is also quite notable that the code was originally programmend on a Sharp MZ-800. Yay! ^^
Here's a video about it, playing a MOD file (link). Not bad for an 8bit machine! 😁

Source: wikimedia.org

Jo22 wrote:

AnacreonZA, I just found something interesting and Covox related.. Perhaps this one is easier to build for you. It's a Covox/Ste […]
Show full quote

AnacreonZA, I just found something interesting and Covox related.. Perhaps this one is easier to build for you.
It's a Covox/Stereo-on-1 clone which uses some NAND-gates, an octal D-type latch, a PIC for the logic
and a Dual 16-bit DAC (TDA1543). Except for the DAC, this is common stuff.

It is described in Martin's 8-bit blog, which has some pretty ModPlay Pro pix.

Build a PC - soundcard second - Covox Stereo-on-1 (Martin's 8-bit blog)
http://www.8bity.cz/2014/postavte-si-pc-zvuko … ox-stereo-on-1/

The original page is in Czech, here's the translation into English.

Schematic, PCB layout and code can be found here.

I found this one recently as well and plan to build one. The TDA1543 is easy to find and cheap on ebay. I ordered some a few days ago.

stamasd wrote:

I found this one recently as well and plan to build one. The TDA1543 is easy to find and cheap on ebay. I ordered some a few days ago.

You're right! Found it - Thanks for the tip! 😁