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Comment by xuhu | Hacker News Reader

Can a 386SX play an mp3 ? Or any CPU without a FPU for that matter ?

From memory a 486DX4-100 or an overclocked 486DX2-66 (to 80MHz) could just about handle 128kbit MP3s

Ah nostalgia... This was my first PC processor. I remember my CPU came with some sort of a bug that prevented me running windows 3.11 on it.

Yeah, I seem to remember there was that brief time period where my PC could barely play MP3s and I used to treat them like zip archives -- rendering them back out to WAV files to play them back.

I think you're right and that was around the 486 DX2, DX4, Pentium transitional time period.

Interesting. My Amiga with a 68030 @42Mhz could just about pull off mono 128Kbps decoding (as long as you didn't multitask too much). That would suggest the 486 was almost clock comparable to a 68030 at least for lossy decompression, perhaps the 486 was around ~110% had their been a 68030 series 80Mhz equivalent.

I wonder if that was also an I/O limitation rather than just a CPU thing. Old floppies probably would not handle 128kbit. Hard drives were slow too, so was memory and bus.

I remember I could play 128kbit MP3s in full quality using mpg123 running under Windows for Workgroups 3.11 ONLY when I overclocked my 486DX4-100 to 120Mhz.

I know a 486 can just barely play them (while doing absolutely nothing else)

Doubtful. Back in the day when my 'work computer' was a Pentium (Pentium 200MMX to be exact) playing a MP3 consumed 50% CPU. Note, I no longer remember if mpg123 was using MMX instructions or not.

Given how much faster a Pentium 200MMX was than any 386 CPU, I very much doubt a 386 (even a DX) would have had enough power to decode in real time a MP3.

I remember using winamp on a Pentium 90 and it was up to the job single tasking. I couldn't say the same about the one time I tried to encode.

I can't recall what hardware I first used an MMX-optimized encoder. I remember it making a huge difference though.

Found this (cubic player on a 386DX at 40MHz) https://www.youtube.com/watch?v=6Jj97NXgHw4 and I'm wondering how much a 32bit ISA is better than a 16bit one for integer decoding.

I used to listen to mp3s on my FPU-less Sharp Zaurus clamshell using madplay [0] with cycles to spare.

Linked from [0] is a page claiming to use MAD for mp3 playback on a Newton [1].

Not sure how those compare to a 386SX, but it's probably a good place to start.

[0] https://www.underbit.com/products/mad/

[1] https://40hz.org/Pages/newton/packages/madnewton/

Even Pentium class CPUs had problems handling MP3s depending on the encoding

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