Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 01:53

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

I found some statement that BOOT1/2 pins are connected to some capacitors which reducing signal distortion (probably have relation to clipping too). Do you mean bridging FEED1 pad to OUT1 pad and FEED2 to OUT2? I couldn't understand what pads you've connected to make it finally work with amp chip …

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 01:13

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

I don't understand why have to bridge those feedback and boot pads, If the amp chip is removed from the PCB, but if it works - it works 😀 Is it worth buying a replacement amp chip for this card?

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 00:48

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

So, the sound clipping is not caused by excessive amplification from TEA2025B chip. I really don't know what else can cause such a problem with this cheapo soundcard. As for the only right working channel - I see that some of the capacitors have been replaced, but it seems like the soldering job was …

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 00:23

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

Ok, then you can now try if the card's output stereo jack will work in something like line-out (non amplified) mode with externally amplified speakers.

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 00:13

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

Did you remove the amp chip?

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Today, 00:07

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

Why you have to bridge those boot pins? On the similar soundcards there are only 2 jumpers for bypassing left and right channels.

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Yesterday, 22:35

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

Yep, remove the amp chip and then connect its left channel input pad to left channel output pad and do the same for the right channel. I really don't know what else you can try if there are no jumpers on the PCB for bypassing the amp. P.S. Now looking at TEA2025B datasheet, I think you can probably …

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Re: ESS 1869F - sound is clipping regardless of volume

Posted on Yesterday, 18:39

by

by analog_programmer

in Marvin \ Sound

in Marvin \ Sound

Try to bypass the amp chip. Anyway its legs look badly soldered.

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Re: Floppy Disks and Bad Sectors

Posted on Yesterday, 15:01

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, several times, with magnets I got from an old ruined IDE hard drive. So, probably there's some damage on the surface of the magnetic disk in the area of track 0 which can't be fixed. I keep one problematic diskette with slight scratch near the middle tracks of the disk. Its track 0 is healthy, …

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Re: Floppy Disks and Bad Sectors

Posted on Yesterday, 11:30

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

However, I had no luck with my two "Track 0 bad disk unusable" floppy disks; they remain unusable. Did you use the magnet on them before formatting? Here is a video with track 0 problem - the guy uses some eraser tool on the diskette, but he also says that any magnet will do the same job: https:// …

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Re: Floppy Disks and Bad Sectors

Posted on 2025-03-19, 19:49

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A permanent magnet only aligns the domains in one direction.. Pulling a permanent magnet away slowly does not cause them to re-align as is the effect from a alternating field. Mind that you don't hold the magnet with only one of its poles pointing to the diskette and by moving the magnet over in …

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Re: Floppy Disks and Bad Sectors

Posted on 2025-03-19, 17:13

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

But the "big" reason to use reducing alternating magnetic fields when erasing media is to reduce the residual magnetic domains as close to zero as possible - any permanent magnet will leave residual domains in other magnetic material when moved in close proximity. And what can guarantee that …

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Re: Floppy Disks and Bad Sectors

Posted on 2025-03-18, 19:33

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A permanent magnet will not alternate the domains, and will leave them strongly oriented in one direction - this may be more than the floppy head can completely re-align, resulting in a less reliable disk. Those neodymium magnets removed from a HDD actuator are not so strong (especially after some …

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Re: Floppy Disks and Bad Sectors

Posted on 2025-03-18, 17:21

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

vico wrote on 2025-03-18, 17:08: Does this method work to fix the error: "Track 0 bad disk unusable"? It should work, if the floppy disk is not physically damaged.

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Re: This 5.25 disk is probably destroyed, right?

Posted on 2025-03-18, 15:52

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Creating an image from a physically damaged (floppy) disk isn't very good idea. If the game's user manual "tells" that you can make a copy of all the files by using COPY command and all the files on the damaged diskette are still readable, then just copy them to another diskette. If you care to …

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Re: Can I use this network adapter to program a motherboard BIOS?

Posted on 2025-03-18, 01:17

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Yes, you can, but the (E)EPROM chip has to be supported by the NIC adapter. There is a limitation in size - 128 KB if I recall correctly.

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Re: "Bios Patcher" questions

Posted on 2025-03-17, 17:15

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi analog_programmer, The first 2 bytes at offsets 0x1D000 and 0x1D001 are indeed part of the ESCD block. These are the first 2 bytes of the ESCD Configuration Header, and represent the size of the stored ESCD data. So the ESCD data of ORIG1.BIN is 0x026D (621) bytes, while the ORIG2.BIN has …

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Re: "Bios Patcher" questions

Posted on 2025-03-16, 21:07

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

When I first experimented with Bios Patcher for the 1st M577 board, I also tried patching with version "6.00.alpha_15". But unfortunately, the BIOS it produced, was freezing during POST :confused: Yeah, unfortunately there's no guarantee that one exact BP version will always produce an working …

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Re: "Bios Patcher" questions

Posted on 2025-03-16, 20:25

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Only "drawback", is that "bla bla bla .. ROM.BY" text at POST, that BIOS Patcher introduces, that screws with the CPU detection line of text. But other than that, all seems good. I always use BIOS Patcher version 6.00 instead of 4.xx with Award 4.51PG BIOSes without any problems, and so far also …

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Re: Mp3 decoder

Posted on 2025-03-16, 15:25

by

by analog_programmer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And here I found some turkish guy who rewrote mp3play for hos own 32bit TRDOS (so he avoided widows :) https://www.youtube.com/watch?v=GoGeS4ul2nw Thanks for mentioning this port. As expected it's for some DIY turkish "real DOS" and completely incompatible with normal variants of "disk operating …

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