VOGONS


CVX4 : high quality covox adapter

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Reply 460 of 470, by Benedikt

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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

You can gladly take my Replicas of Covox Speech Thing, FTL Sound Adapter and SiliconSoft SoundJr as inspiration and e.g. put a PCB with SMD components and a low-profile audio jack in a plug case.
They were supposed to be reasonably accurate replicas, but designing something that looks like the SoundJr without the bus-powered transistor amplifier would surely be an option for a new Speech-Thing-like device. The only downside is that you have to hand-solder the edge-mounted DB25 connector.
(Btw.: You have all three of them, don't you?)

Reply 461 of 470, by digger

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FreddyV wrote on 2022-02-07, 12:45:

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

A nice improvement over the original DSS would indeed be the ability to adjust the FIFO buffer size and the output frequency. The original DSS had a fixed 16-byte buffer and a non-adjustable output frequency of around 7kHz. This resulted in sound effects sounding somewhat lower-pitched and slower in some games that officially supported the DSS, but didn't bother to down-sample the sound assets, which were often recorded at 11kHz. Being able to tweak the buffer size and playback frequency would help with these games, and would be a nice improvement over the original design overall.

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

Aside from the required complexity for such a solution, it would limit compatibility to parallel ports that support ECP. Also, there is no existing software support for such a mode.

A compromise would be some kind of enhanced mode hat would use the IRQ line of the parallel port as a more efficient way to inform the software that the FIFO buffer is full (or empty). (As opposed to having to poll the state of one of the status pins, which Is the case with the original DSS.)

But before we blow up the scope too much: just a single device with software-switchable Covox speech Thing and Disney Sound Source compatibility would already be wonderful. With adjustable FIFO buffer size and playback frequency being low-hanging fruit w.r.t. improvements over the original standard.

Reply 462 of 470, by ViTi95

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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

- Full DSS support (FIFO + 7KHz sampling)
- Stereo COVOX support
- Funky LEDs because why not?

Reply 463 of 470, by ultramars

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- a serial port, like on the FTL sound adapter:

photo.jpg

So that for example we can connect a mouse AND an MPU-232 on the computer 😎

this would be more usefull nowadays than the pass-through parallel port of the original covox, i think...

Reply 464 of 470, by dreamblaster

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ViTi95 wrote on 2022-02-08, 12:48:
- Full DSS support (FIFO + 7KHz sampling) - Stereo COVOX support - Funky LEDs because why not? […]
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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

- Full DSS support (FIFO + 7KHz sampling)
- Stereo COVOX support
- Funky LEDs because why not?

Hi oh
this is going way beyond simple unpowered covox
maybe i do something like that as a different project.
how about just make some more CVX4, or minor changes to it ?
does anyone use the filter settings ?

Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
New X2GS sound card : https://www.serdashop.com/X2GS
Thanks for your support !

Reply 465 of 470, by digger

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dreamblaster wrote on 2022-04-03, 11:58:
Hi oh this is going way beyond simple unpowered covox maybe i do something like that as a different project. how about just make […]
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ViTi95 wrote on 2022-02-08, 12:48:
- Full DSS support (FIFO + 7KHz sampling) - Stereo COVOX support - Funky LEDs because why not? […]
Show full quote
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

- Full DSS support (FIFO + 7KHz sampling)
- Stereo COVOX support
- Funky LEDs because why not?

Hi oh
this is going way beyond simple unpowered covox
maybe i do something like that as a different project.
how about just make some more CVX4, or minor changes to it ?
does anyone use the filter settings ?

Stereo-on-One compatibility, perhaps? That shouldn't be too hard to implement. The README of the Crystal Dream demo has a schematic for it:

You can now play Stereo on a D/A converter in the parallell port. This
requires an improved D/A converter with a REAL D/A, it won't work with
resistors.
(...)
here is a drawing.
You can find the components in for example ELFA. It should work
(it does for me), but don't blame me if you burn your parallell port...

Mr. H

+ 9-12 V
├──────────┐
To │ │
parallell │ 3.3kΩ To amplifier:
port: ┌────┴───────┐ │
│ + RefA├──┼── 22kΩ ── - ≈ 0.1µF
1 ───────┤A/B RefB├──┘┌──────────────────────┤├────── Left ch.
│ │ │ ┌────┐<-- ¼ LM324
LSB 2 ───────┤DB0 RfbA├───┴─┤Out ├──── -
: │: OutA├─────┤-IN │ +
: │: │ │+IN ├──┤
: │: Agnd├───┐ └─┬──┘10kΩ
MSB 9 ───────┤DB7 OutB├──┐└───┤ │
│ RfbB├┐ │ ├─────┴─ 10kΩ ─┬ -
PM7528HP -->│ ││ │ ┌─┴──┐ │
│DGnd CS WR ││ │ │+IN ├───────────┴─────────── Gnd
└─┬───┬──┬───┘│ └──┤-IN ├──── +
25 ─────────┴─┬─┴──┘ └─┬──┤Out │
│ │ └────┘<-- ¼ LM324
│ │ ≈ 0.1µF
- └───────────────────────┤├────── Right ch.

The pins in the parallell port is used as follows:

1 - Selects left or right channel
2 to 9 - 8 data bits (2 = Least Significant Bit , 9 = Most ...)
14 - Pin 1 inverted (isn't used in my D/A, but may be useful)
25 - Ground

See also this thread by matze79, about a prototype he made based on this design.

Reply 466 of 470, by dreamblaster

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it sounds and works well as it is... so in the end,
I made a new batch of CVX4, Vogons Tuning Edition...
Available now again at https://www.serdashop.com/CVX4

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Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
New X2GS sound card : https://www.serdashop.com/X2GS
Thanks for your support !

Reply 467 of 470, by dreamblaster

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Made a new video showing Lunatic demo (from 1993, Extreme) played on CVX4 : https://youtu.be/HNt5Tlx6sAY

Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
New X2GS sound card : https://www.serdashop.com/X2GS
Thanks for your support !

Reply 468 of 470, by dreamblaster

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the new black/blue printed enclosures arrived

also I bumped into this video : MP3 playback under dos, using CVX4 : https://youtu.be/d46nYXDt4xE

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Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
New X2GS sound card : https://www.serdashop.com/X2GS
Thanks for your support !

Reply 469 of 470, by digger

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If it ain't broke, don't fix it. Fair enough. And I'm sure there's still good demand for a no-frills high-quality Covox Speech Thing clone.

But still, could at least some of these proposed improvements make it into a hypothetical CVX5?

Reply 470 of 470, by FreddyV

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dreamblaster wrote on 2022-05-22, 15:43:

Made a new video showing Lunatic demo (from 1993, Extreme) played on CVX4 : https://youtu.be/HNt5Tlx6sAY

Hi,

You sent me some devices to implement in Mod Master, but you have not done video with it so far 😀