WAV audio to EPROM Blower-by SM0VPO

Ruud wrote:

One trick I did do was to ... :-)

Are you serious? I think it is a rather unusual way to edit a binary file in MS-Paint!...
(Personally I use a hex-editor for that.)

Yes, I am absolutely serious. It takes but a few minutes. Although it is a "klick exercise" st do the final save, you get to edit complete columns in picture format. You can take 16-bit and make 8-bit, remove a stereo channel. It is perfect for swapping text round.

The final text cut from PDF to TXT generates a file that you only need to paste in the EPROM locations before each line and load directly into your EPROM burner.

Do not forget that you are not editing the binary itself but simply copying the blocks of bytes you want. You can cut/past blocks vertically or horisontally. Whats more you do not need to buy any software, s long as you have a WYSIWYG word processor.

Best regards from Harry

One trick I did do was to wind my screen res to max and do a BMP screen dump of a WAV file. In a picture editing program (eg. PAINT.EXE) you can delete alternate vertical rows and push the gaps together. Paste (import) the picture into MS-WORD, save as PDF and then you can cut'n-paste the text back into a TXT file from the PDF viewer :-)

Are you serious? I think it is a rather unusual way to edit a binary file in MS-Paint!...
(Personally I use a hex-editor for that.)

Hi Harry,
good recording programs should give you selections between 8 and 16 bit precision, mono and stereo, and the sampling rate.

VBR from Ivan

Analogue1 wrote:Hi Ruud
Thanks for that. I will try that, but, as I said, I'm alittle rusty om digi stuff. Have u any circuit suggestions for these please

Regards

A

 To get 16-bit audio simple connect two EPROM control and address in parallel, but use the D0 to D7 as D0 to D15 (8+ using the resistive D to A converter.

In a different description, buikd a 8-bit as shown and "piggy-back" a second EPROM on the first after seperating the Data pins.

As regards the binary file, read it as 8-bit but there are 2x 8-bits to a 16-bit word. Then the next two 8-bit bytes are the left-hand channel.

One trick I did do was to wind my screen res to max and do a BMP screen dump of a WAV file. In a picture editing program (eg. PAINT.EXE) you can delete alternate vertical rows and push the gaps together. Paste (import) the picture into MS-WORD, save as PDF and then you can cut'n-paste the text back into a TXT file from the PDF viewer :-)

BR Harry

My advise: just start with the project!
There is really not very much that can go wrong.
Simply start with the 8 bit version as Harry described.
If it works, try to change the clock frequency and maybe the audio filter capacitor.
At the moment you have got more experience with the circuit, you may exchange the EPROM for a bigger type (longer play duration) or even change (or cascade) the counter to drive the extra bits for the EPROM inputs. Doing things = learning! (And fun!)
Start simple and build from that.

Hi Ruud
Thanks for that. I will try that, but, as I said, I'm alittle rusty om digi stuff. Have u any circuit suggestions for these please

Regards

A

I once used the same principle, but with two EPROMS and two R-ladders.
Both EPROMS were driven from the same counter.
Also I used a 16-bit WAV file. One EPROM contained the 'high' bytes, the other EPROM the 'low' bytes. By adding the outputs of the R-networks in the correct ratio, I got a 16 bit resolution. (A better audio quality!)

I must add that it is always refreshing when others take my projects and expand on them. It would be nice of you could also post the results of your modifications.

A others pointed out, just extend the memory and increase the speed for a higher bit-rate. But without compression this will eat memory.

BR Harry

Hi Paul,
it should be enough. Increasing the sample rate extends the bandwidth (eventual filtering should match the maximum AF), but shortens the play time. Extending the address counter and using a "longer" memory prolongs the play time.

BR from Ivan

I don't see a problem in changing the clock frequency.
As long as the audio file is 8 bits, it should work.
There is almost no filtering (only the 1 nF capacitor), but you could change the value of the capacitor.

Hi All
Just wondering if it was possible to expand this circuit  http://www.sm0vpo.com/eprom/wave_00.htm  to 1 second or 0.5 seconds and up the sample rate to 16-20K
I am an old analogue head, and would appreciate some input on this. I suppose just upping the clock/sample freq and changing the filter frequencies is not enough?

Cheers

Paul