cvx4fanboy wrote:

Hello. I've got a CVX4 thing and cvxplay program. It does work and I can play sampleu.raw.
One thing I couldn't figure out yet is how to convert mp3 or wav to this covox raw format.
Could you please explain this to me?

You can use the free Audacity program for this: https://www.audacityteam.org/
Open your mp3 or WAV file, then use the Export function from the file menu. Export the audio as a mono 8-bit unsigned raw PCM file.

you can play mp3 directly on cvx4 without converter. (at least Pentium required..)

Requires CWSDPMI:
http://sandmann.dotster.com/cwsdpmi/

if you want you can add Support to your Covox for FTL Sound Adapter.

Just adding a Wire gives you Sound in Dungeon Master.
Gave me some headattache but now i found out how it works..

Wire from Pin 17 to Pin 12 on your Covox Clone

And it works:
https://youtu.be/8-qID0qEmMs

Why would it? The FLT sound adapter is fully documented.
http://dmweb.free.fr/?q=node/1514 (schematic is kinda meh to read)

Uff did not read this 😀

Speaking of the FTL Sound Adapter...

That device uses a 25.5kΩ load resistor and I reckon the Speech Thing uses 25.5kΩ, as well. I'm therefore going to use 25.5kΩ for my own replicas (new thread).
MobyGamer's measurements strongly support this assumption:

MobyGamer wrote:

Well, that was educational: […]
Show full quote

Well, that was educational:

CVX-1 Prototype: 5.04 vDC
CVX-2 Prototype: 4.80 vDC
10-pin Covox: 1.024 vDC
11-pin Covox: 1.025 vDC

With an input voltage of 5.04V and a 25kΩ load we should get an output voltage of
5.04V * (1 / (1 / 100kΩ + 1 / 25kΩ)) / 100kΩ = 1.008V

That is -1.5625% away from the 10-pin Covox and -1.6585% away from the 11-pin Covox.

With 25.5kΩ, however, we get
5.04V * (1 / (1 / 100kΩ + 1 / 25.5kΩ)) / 100kΩ = 1.02406374502V

That is just 0.0062% away from the 10-pin Covox and -0.0913% away from the 11-pin Covox. I'd call that bang on.

i`m working on a combatibility list of covox software:
https://shadowcircuit.de/phpBB3/viewtopic.php?t=12

i test every piece by hand, so i`m 100% sure it works.

matze79 wrote:

i`m working on a combatibility list of covox software:
https://dosreloaded.de/forum/index.php/Thread … liste/?pageNo=1

i test every piece by hand, so i`m 100% sure it works.

That's great, I wish this forum wasn't in german 🤣
When you finish your project, could you also share the result here in vogons with a column on how to setup the application/game for covox?
eg Electro Man | setup option
Star control | cmd line param: /s:lpt<x>

Again, great idea

yeah thats the plan 😀

but first i go straight trough mobygames list.

Did someone try CVX4 on a IBM PS/2 9577 ? Does this have 'special' parallel ports ?
I received a report, it didn't sound good on that machine.
Same CVX4 sounded great on his other PC.

Remember that issue I had where the lack of a pull-up resistor meant the OPL3LPT device didn't work right on some of my systems? Do you think it might be related to this?

Also, the PS/2 Model 77 is microchannel; some software might not work correctly on it vs. regular ISA, EISA, VLB, or PCI systems. I'd ask him what software he was using to test it.

The list of games with Covox support will increase substantially when you include all the games that used AIL2 or DIGPAK drivers.

There is a DIGPAK driver for the Covox Speech Thing that can be used as an AIL2 driver as wel, simply by replacing an existing AIL2 DAC driver (for instance the Sound Blaster driver) with it, using a patch utility, or in the case ofsome games simply by overwriting the driver file with it, renaming the DIGPAK .COM file to the .ADV driver you're replacing.

Someone in another Vogons topic tought me that trick. Pretty neat. 😀

MobyGamer wrote on 2020-12-28, 19:28:

Remember that issue I had where the lack of a pull-up resistor meant the OPL3LPT device didn't work right on some of my systems? Do you think it might be related to this?
Also, the PS/2 Model 77 is microchannel; some software might not work correctly on it vs. regular ISA, EISA, VLB, or PCI systems. I'd ask him what software he was using to test it.

Yes it could be the same port difference, causing issues for CVX4.

Retiring the current revision of CVX4 to the museum.
If you still need current revision CVX4 or its enclosure, pm me.
(I have a few left for the bundle, which is still available at the moment)

I will make a new version CVX4 V2, later on.

FastDoom Supports Covox now 😉

hello,

dreamblaster wrote on 2021-07-11, 11:04:

If you still need current revision CVX4 or its enclosure, pm me.
(I have a few left for the bundle, which is still available at the moment)

still available? what price?

ultramars wrote on 2022-02-01, 02:53:

hello,

dreamblaster wrote on 2021-07-11, 11:04:

If you still need current revision CVX4 or its enclosure, pm me.
(I have a few left for the bundle, which is still available at the moment)

still available? what price?

ok i had a look, i still found a few CVX4 in my stock, and I added the bundle again to the webshop (only 2 times available) : https://www.serdashop.com/Special-Parallel-Port-Bundle
and I will also keep one CVX4 apart if you are interested, pm me.

I'm thinking of making a CVX5, any suggestions for changes/improvements compared to CVX4 ?
CVX5 would be available in larger amount, it will take a few months though

dreamblaster wrote on 2022-02-06, 09:18:

I'm thinking of making a CVX5, any suggestions for changes/improvements compared to CVX4 ?

1) RCA connector(s) on all of your audio devices instead of minijack: it goes real quick to pull the cable out wrong or just accidentally pull on the cable, resulting in bad contacts with the minijack plug that has become too loose. This is less likely to happen with RCA's
2) from what i saw of the pictures of the casing of the OPL3LPT or MPU-232, those are more covers than protective casings: if you look at the shell of a DB25 plug, it's usually firmly attached to the connector itself, while on your designs, if anyone bumps/press on the device, the stress will be put on the circuit board and/or computer parallel port connector as it seems to me.
It would be great to have a rigid enough casing firmly attached to the parallel port & computer via the screws, to better protect the electronic circuit inside.

For the rest, i read the whole thread, heard the available listening examples and i guess everything has been pretty much thought about. The dip switches to switch between capacitors to adjust the lowpass filter cuttoff regarding of the sample rate versus mixer/amplifier's input impedance & cable inductance is a really great feature ! 😎

See this home brewed covox clone self contained in the DB25 plug shell AND with a RCA connector 😉

dreamblaster wrote on 2022-02-06, 09:18:

I'm thinking of making a CVX5, any suggestions for changes/improvements compared to CVX4 ?
CVX5 would be available in larger amount, it will take a few months though

How feasible would it be to include Disney Sound Source compatibility in a CVX5 design?

I know you already mentioned that a DSS clone is in the pipeline, but having both Covox Speech Thing and DSS compatibility in a single device would be quite convenient, especially if it could somehow be made software-switchable between those two modes.

I recently acquired an original Disney Sound Source in a well working state. I'd be willing to lend it to you (long term even), if that would aid you in debugging and compatibility testing.

The best would be to do a Disney sound Source like, With a bigger buffer and increased output frequency.

It is also possible to do a Parallel port "Covox" with DMA Support, as the parallel port support DMA.