It's been so long since I've looked into this stuff ... but I have a vague memory that some early CD drives had a connector for audio output decoded by the drive internal electronics (after all CD was originally designed for storing digital audio not data)

As for IDE<>SATA, I would think that both would be more than enough for audio streams ... errors would be unacceptable on either.

But I don't know intracies of current methods of extracting audio tracks from CDs - perhaps IDEs support a method that Sata doesn't?

Most SATA drives do not have an audio output.
If you use the headphone jack on the front or the sound card output on the back, quality is dependent on the DAC inside the drive. If you use the SPDIF output, you'll get pretty much the same thing out of any drive (unless the disc is in poor shape and the drive has bad error concealment).

DaveDDS wrote on 2026-07-15, 13:58:

It's been so long since I've looked into this stuff ... but I have a vague memory that some early CD drives had a connector for audio output decoded by the drive internal electronics (after all CD was originally designed for storing digital audio not data)

As for IDE<>SATA, I would think that both would be more than enough for audio streams ... errors would be unacceptable on either.

But I don't know intracies of current methods of extracting audio tracks from CDs - perhaps IDEs support a method that Sata doesn't?

My PC knowledge is pretty much foggy pre-2014 as I grew up a console kid but considering that I do have a few different optical drives (DVD, Blu-ray, UHD, IDE, SATA) now, I've noticed and used the CD Connector before but I don't know enough details on why modern retro enthusiast still use it. Maybe that's the key to why you can find these IDE display connectors rather than SATA ones. I'm also wondering, if you go with an IDE to SATA converter, if you defeat the purpose of the project because there might be something better with using the IDE drives.

From past articles and forums that I've read, you get these kind of weird scenarios with things like consoles, especially SONY. Where there first 2 versions of a given console have the more premium optical drive, but then as they bring the prices down, they switch to standard drives due to the assumption that the extra features won't be used and it's worth cutting the cost.

jmarsh wrote on 2026-07-15, 14:42:

Most SATA drives do not have an audio output.

aaahhhhhhhh, ok. I may need to see if there are any videos or written out guides on what the connector does and doesn't do to better understand it all.

iiamsiincere wrote on 2026-07-15, 14:47:

jmarsh wrote on 2026-07-15, 14:42:

Most SATA drives do not have an audio output.

aaahhhhhhhh, ok. I may need to see if there are any videos or written out guides on what the connector does and doesn't do to better understand it all.

Around Windows 2000 times, PCs switched from "analog" to "digital" audio CD playback.

Digital means that the audio CD is "ripped" (the 44100 Hz x 2 channels x 16 bits per sample uncompressed audio data) into memory, sent out to the sound card, and then thrown away.
If someone wanted to upload a track to a filesharing site, they would start with the same process, but instead of playing it and throwing it away, the audio data would be fed into an MP3 encoder instead.

Older PCs didn't have the bus/memory bandwidth or CPU time to spare to do this. Instead, they just send a command to the drive saying "play track 1", and the drive, like a CD player, just outputs analog sound either to the front headphone jack or the rear internal jack. The rear internal jack has a little bypass cable going directly from it to the sound card, so the CD audio is just another analog source that gets mixed in to the sound card's output.

jakethompson1 wrote on 2026-07-15, 14:56:

Around Windows 2000 times, PCs switched from "analog" to "digital" audio CD playback. […]
Show full quote

iiamsiincere wrote on 2026-07-15, 14:47:

jmarsh wrote on 2026-07-15, 14:42:

Most SATA drives do not have an audio output.

aaahhhhhhhh, ok. I may need to see if there are any videos or written out guides on what the connector does and doesn't do to better understand it all.

Around Windows 2000 times, PCs switched from "analog" to "digital" audio CD playback.

Digital means that the audio CD is "ripped" (the 44100 Hz x 2 channels x 16 bits per sample uncompressed audio data) into memory, sent out to the sound card, and then thrown away.
If someone wanted to upload a track to a filesharing site, they would start with the same process, but instead of playing it and throwing it away, the audio data would be fed into an MP3 encoder instead.

Older PCs didn't have the bus/memory bandwidth or CPU time to spare to do this. Instead, they just send a command to the drive saying "play track 1", and the drive, like a CD player, just outputs analog sound either to the front headphone jack or the rear internal jack. The rear internal jack has a little bypass cable going directly from it to the sound card, so the CD audio is just another analog source that gets mixed in to the sound card's output.

Oh ok. This makes more sense as to why you would want an IDE drive instead as you want to send the "analog" information straight to the output (whether powered or passive speakers). I hope I'm understanding that correctly.

Yes, and it also makes it easy to play .wav (potentially at a different sample rate or number of channels than the CD audio) sound effects over top of the background audio CD track, since the mixing is just done in analog on the sound card.

jakethompson1 wrote on 2026-07-15, 16:09:

Yes, and it also makes it easy to play .wav (potentially at a different sample rate or number of channels than the CD audio) sound effects over top of the background audio CD track, since the mixing is just done in analog on the sound card.

You're referring to the Drive being used in a normal computer setting correct? In this case, in regards to the DIY project I found, it would strictly be used as a CD player/Transport device.

Yes, you will speak ATAPI to the drive which is essentially SCSI over ATA.
Within the ATAPI layer are SCSI MMC commands you can look up.
For an example here, Re: Throttle CD-ROM drive speed in DOS? is the SCSI MMC "set cd-rom speed command" (to slow down noisy modern drives), which ends up being the bytes, BB 00 05 88, to set a transfer rate approximating 8x.
There are other MMC commands to play audio tracks.
Note there were some IDE CD-ROM drives with playback buttons on their front next to the headphone jack, that might already do exactly what the DIY project does.

Yup. This is just re-adding analog cd audio functionality to a cdrom drive.

Vintage drives have this functionality. Modern drives do not, because digital mixing is easier and cheaper.

Analog *used* to be easier and cheaper.

Some CD and possibly DVD drives also had a 2-pin digital audio out next to the 4-pin analog audio out.

For the analog audio out, the drives have a DAC built-in.

SATA drives , as mentioned earlier, mostly eliminated the audio out ports on the rear of the drive as the OSes then just grabbed the data from the audio tracks and used software or hardware to play back the CD audio tracks.

IDE drives can also do this, but it is dependent on the OS. Looks like prior to Windows 98 and early Linux don't have the capability to do this. This is why the audio out connections were on the back of the drives.

Having the audio going through the data connection is called digital audio extraction (DAE) or digital CD audio.

iiamsiincere wrote on 2026-07-15, 12:46:

When it comes to audio quality, for those who know, which would be better...IDE Optical drives or SATA Optical drives? And this is assuming that you're comparing higher quality drives of each type.

They were all commodity DACs, as long as the CD drive made music sounds people were happy. If you were interested in making a 'high end' PC CDRom based player you can find a drive that has digital output, do a TTL to SPDIF conversion and include your own DAC of choice.

Me personally I don't think the difference is worth it when dealing with CD audio. Even budget DACs and CD players sound fine.

Some very late IDE/ATAPI optical drives also lack the analog and digital Audio-CD outputs (even with the connector footprints populated). You have to be a bit careful if you intend to buy one.

The internal dac is specified in such a way that it does not cost them money to add it. A quite obvious difference can be heard between digital via sound card dac and analogue via cdrom dac - the cdrom sounds dull and the sound card crisp and sharp (sharp in the HF response, not tonal kind of way) in comparison.

IDE drives can be found that are slower than SATA versions times the original CD rotation speed and sought after by retro gamers who still use older games but don't
want the high speed vibrations from more modern versions.
However software tools can slow down modern fast optical drives.
SATA optical has the advantage of not slowing down other SATA devices. If you have an IDE hard disk on the same data cable as an IDE optical drive that disk will
slow down to the same data speed and some retro sound cards had their own IDE port to keep the CDROM off the system IDE ports.

Well that was halfass correct in that a PATA IDE channel will work at the slowest mode of devices on it, not necessarily because one of them is optical, so put ATA-33 device on an ATA-100 channel and that channel runs ATA-33. This is true whether you've stuck an optical or a harddrive ATA-33 on it. However, opticals with faster interfaces were around, and you can do an all ATA-100 setup if you find the capable drives. Though cable rot often shoots you in the foot here and you don't find nice crisp ATA66/100/133 cables so easily now.

The IDE interface on soundcards appeared before any of this was much in question, due usually to machines at the time only having one ATA interface, such that an additional one was useful. Also to ensure that it was fully ATAPI as the CD required when some older machines only supported an early AT interface without the extended command set necessary (This is frequently encountered when trying to use a sub 100MB drive with a CD on same channel, they don't play nice because HDD forces older AT protocol and/or doesn't have compatible M/S settings). They were actually disappearing off soundcards into the ATA66 era when the disparity between HDD interfaces and optical drive interfaces began to show. Even then it was usually a case of your old carryover optical slowing the bus, not the fact that you couldn't sensibly spec a system from new parts to be just as fast either way. But HDD were much bigger by now and there wasn't a lot of reason to need to share the secondary IDE with a HDD. Beyond the "playing nice" with the fastest protocols though there wasn't much impetus to upgrade interface speed from the optical drive's data transfer requirement's POV. i.e. they were too slow to saturate ATA 33 or even DMA mode 2 for years. Thus they did tend to lag behind maximum available HDD speeds... but then so did motherboards unless you were upgrading every 6 months.

BitWrangler wrote on Yesterday, 14:28:

some older machines only supported an early AT interface without the extended command set necessary (This is frequently encountered when trying to use a sub 100MB drive with a CD on same channel, they don't play nice because HDD forces older AT protocol and/or doesn't have compatible M/S settings).

I don't follow. On a plain ISA Multi-I/O card, the IDE interface is just a direct connection to the ISA slot, with some 74 series logic in between to generate CS_1FX# and CS_3FX#.
It should be completely agnostic to the ATA and ATAPI commands travelling over it.
I grant you though, since the "master" drive has to correctly ignore commands when the "slave" is being addressed, and "slave" detection wasn't formalized until ATA was made official, two drives on the same cable can certainly be a problem even when it shouldn't.
If the IDE interface is a caching controller or otherwise something other than a direct connection to ISA, it could choke on ATAPI as well.

Not entirely sure if BIOS gets in the way or whether there's some signals left off, know it should be almost pure AT bus. Or maybe buffers, like 74 series, other than cache knock off critical signal timing if they're not on all lines.

Another pain of a cdrom sharing a chamnel with a disk is when the cdrom pulls busy while revving or struggling to read, the channel is engaged and the disk io must wait. Especially terrible if it is the operating system disk.