My first MP3 player was the very first Rio PMP 300, with whopping 32MB (note; megabytes, not gigabytes!) of memory. Even at lousy 128kbs it couldn't hold even single full CD's worth of music. Also it had to be connected to PC via parallel port, which always was a pain in the behind, especially since it's PC software pretty much sucked. Nevertheless it was infinitely better than portable cassette or CD players.
Come to think of it, I'm not sure what happened to my Rio actually. It might still be around somewhere, or maybe I've ditched it. I'm mildly interested on seeing what's inside it, although I'm pretty sure it offers no surprises (and most likely has been dissected to death multiple times already).
Later I have had several players, but I'm quite sure that the one I've used most is Pontis SP600 (I think this was the exact model). It had some internal memory and CF (CompactFlash) and SD card slots. The main reason for longevity was that it was pretty much best audio book player (for me) I had used so far - for example iPod required audiobooks to be in AAC format, which in my opinion was and simply is simply absurd and braindead requirement. Granted, overall Pontis was not that great, as you couldn't listen to, say, music and then continue with the book from where you left off, but as I used mine as audio book player exclusively, that was no issue.
Digging through drawers I happened to find it now, and since it's pretty much retired I decided to see what was inside (aside the CF card which still had last audiobook I listened on it)
Pontis used single AA battery (accepting also rechargeables which I used the most). I'm not sure what was the promised playback time but I remember always carrying at least two spare rechargeable NiMH batteries when going for longer walk or (bicycle) drive as current battery way too often became suddenly empty (and sometimes my first spare was already empty, d'oh...). Battery going empty shouldn't be a problem, but annoyingly when that happened the player didn't store the position within current file before turning off -- so you had to fast forward a long time (as the fast forward worked at rate of 10s per second or so). That is, unless if you hadn't paused every now and then (letting player turn itself off for inactivity, thus storing current location). And yet I consider this lesser PITA than dealing with mess of iTunes and AAC.
Remembering this frustration (and some discussion lately about a certain battery booster gadget) at eevblog I wanted to see how voltage Pontis could use and was pleasantly surprised. Pontis would only turn off when battery voltage dropped below 0.8 volts, using pretty much all juice that you could have in one. It wouldn't start up below 1.0 volts but I don't think that as a problem -- at that point battery is already fairly low so there's not much listening left anyway before change.
Since the point of turning off is that low, I actually suspect that player has some subtle bug in their low battery detection system that causes its regulator to turn off before the main MCU ever gets notified of the situation. Not very nice, and situation that I would have expected them to test and handle properly.
Current consumption was quite high though - at 1.6 volts it used 250mA when playing audio, and at 0.8 volts consumption was at 440mA. With these figures you'd be happy to get six hours of play time from you typical cheap AA battery, which I think is fairly close to my experience.
When off it still used about 50 microamps; while not a great figure, I consider it acceptable, especially considering it's age - quick search suggests this was released around 2004 or so.
Circuit board on topside. Nothing too fancy. The display module is mounted on plastic stands, underneath there wasn't anything too interesting. On right side there's wheel/button (underneath PCB) and buttons.
One point of note is nice battery terminal attachment. Sorry for not having larger picture of those, but essentially there is a slot in the PCB at the contact point, through which the terminal is pressed and soldered in place. Way more rugged than your typical surface mount terminal.
I couldn't find any layer markings on PCB, and trying to see layer stack from edge wasn't easy either. I'd guess either 4- or 6-layer board; packing this much stuff that densely on 2-layer board might not be impossible, but it would be damn difficult. Even if this looks like highly integrated and packed solution, compared to current offerings this is actually very loosely packed PCB.
On bottom side there's main MCU TMS320Vc5416 a DSP processor that runs at 3,3 volts. Remember I said that player works with single AA battery? That is handled by boost converter near the battery using MAX1701. On quick glance the chip does have low battery signal, but somehow that isn't handled properly - or maybe it only activates when battery is already too low for safe power off.
Next to MCU is a flash chip. I don't remember if player had internal memory or if that is for software. Around the board there are also several 74-series chips; shift registers, multiplexers and such, most likely to make up limited pin numbers on MCU (flash and display both need fairly large amount of I/O)
USB interface has now-obsolete four-pin mini-B connector. USB communication goes through PCIUSBD12 chip so the main processor doesn't have to care about that. Actually, back then MCUs with built-in USB weren't that easy to get, especially if you wanted low(ish) power consumption, so this setup actually makes sense.
So nothing very surprising here really. Moving on...
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