BEEN_Nath_58 wrote on 2022-10-13, 13:52:
BitWrangler wrote on 2022-10-11, 14:51:
Without an audio cable in 9x upward, it's just reading and decoding raw data through the IDE interface as if it was ripping the disk. This has a lot of CPU overhead. So even if you've got Win98 running and the digital decoding enabled, you will tend to have problems running games with high CPU demand and CD Audio, since it will put extra demands on CPU.
So having no audio cable through to soundcard is equivalent to putting the CD-ROM connected directly to the motherboard and making the CPU do reading and decoding, just like most media players today?
Yes, it's a very minor load for modern CPUs. Not so minor for pre year 2000.
BEEN_Nath_58 wrote on 2022-10-13, 13:52:I would love to understand this situation better:
1) What does the drive DAC do? shouldn't CPU be doing DAC functions, just like […]
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BitWrangler wrote on 2022-10-11, 14:51:
While it seems like you should have higher quality CD audio through the IDE audio decoding.... you probably don't. The drives with analog audio jack will have the CD quality 48khz DAC in there, which will pipe through direct to output on your soundcard with the audio cable, but if you play it through the IDE decoding, n ot only is there the 1.4Mbit/sec "tax" on the i/o, you'll only play it out as well as your soundcard can though it's DAC, so it might be limited to 44khz or 22 khz even. By the turn of milenium higher end soundcards might be better though.
I would love to understand this situation better:
1) What does the drive DAC do? shouldn't CPU be doing DAC functions, just like a soundcard would with it's DAC (considering you use the audio cable)?
2) why does "you'll play it out as well as your soundcard can through it's DAC" if I use IDE channel? Shouldn't the Taxed I/O introduce stutters instead of lowering the quality?
Something needs to make the digital data into analog audio at some point, the DAC in the CD drive makes it into analog that can be taken out of the rear header, or the front jack if equipped, it does this with a 16bit DAC capable of 48khz sample rate. If you connect the analog to the soundcard, it's connected more or less in parallel to other sounds the cards makes, but may go through a small amplifier with them, if it has one. If reading digital through the IDE cable, something has to turn it into analog audio at some point and that something is the soundcard or onboard audio, and it can't do a higher bitrate than it's designed for so there may also have to be downconversion performed by CPU before it can be played. This only applies to earlier soundcards, such as SBPro 2 class, SB16 class, later soundcards had faster DACs so could play the digital audio stream at the same rate it was stored at. So the quality lowers if a card with a slower DAC does the conversion and ALSO the demand on I/O and CPU may introduce stuttering in high load scenarios.
BEEN_Nath_58 wrote on 2022-10-13, 13:52:
BitWrangler wrote on 2022-10-11, 14:51:
Also an issue is older drive might not actually support DAE digital audio extraction... so you get a classic 8x and stick it in a newer machine with no CD audio input and you can't play audio CDs (unless you stick headphones in it's front jack if it's got one)
Since I heard DAE for first time, does it mean "sending analog audio data to a computer through a data bus"? Is there any general speed rating such as 16x, 24x, which makes sure DAE is supported?
It means the capability of the drive to read the digital audio tracks in data mode so it can pull the digital data through IDE... it's a fuzzy boundary where DAE Digital Audio Extraction worked and didn't, it was a high end feature very early on, some 1x 2x SCSI drives for professional market may do it, but it was less common in early IDE drives up to 8x, then more common thereafter, though there were still drives that didn't do it... mostly made by companies that had relationships with the music recording industry.
BEEN_Nath_58 wrote on 2022-10-13, 13:52:
BitWrangler wrote on 2022-10-11, 14:51:
Rare drives however also have an SPDIF digital, which requires a soundcard or onboard sound that can speak that, I think it's less CPU overhead, all being handled by custom hardware, but don't mess with it myself.
Isn't this what Joseph explained earlier?
Yuo, though I was referring to pre-2000ish classic era as it being a rarer feature then, it did become more common later.
BEEN_Nath_58 wrote on 2022-10-13, 13:52:
1) There are CD drives with a volume button in front. Does that change only the CD music volume in application or the volume of entire computer?
2) WinMM emulators have an emulate cd Aux option. I assume Aux is some supplimentary hardware or button for the CD music. Can you tell what's an Aux device related to cd music?
That changes the analog volume at the drive, it may only affect the headphone jack or may affect the rear analog. If it's right next to jack, probably only that.
Aux usually means auxilliary input, the kind of thing you plug an analog CD audio cable into. So it would emulate it as an analog input.
Edit: as Joe says, the front panel controls are independant of software and drivers on the computer. One can use a CDROM with front panel controls as a standalone CD player, it only needs power and some connection to amp and speakers, whether you make a line in cord that fits the analog header at the back, or use a cassette adapter plugged into the headphone jack on front or something.
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