got this crazy idea that I was wondering if any of you could throw some thoughts towards it. I thought it woul dbe cool if you could plug one of those Rio personal portable player things to the USB jack on the empeg unit and "upload" some songs to the unit. That way you could drive wherever you're going, upload some songs and keep on listening to those mp3s

The empeg car has only a "slave" USB port, not a "master" port. It cannot act as a host to portable devices.

And by the way, in case anyone else ends up answering this question while I'm not around, I just put up a new FAQ entry up on the topic that you can point folks to.

Would it then be possible to use the serial port if the portable mp3 player also had such capabilities?

Serial would be possible, but it would be terribly slow, and you'd have to write the driver software for it. Any good at coding under Linux?

Besides, which portable players use serial anyway? I can't think of any.

the orginal diamond rio, i have it sitting right here on my desk.. serial port.. WOOHOO!

hey...I got one of those too...

Parallel port, I think you'll find.

The pontis mplayer3 had serial, and was thoroughly slagged off in reviews for having a longer-than-real-time download speed!

Hugo

Yes, parallell.
I remember being quite impressed by the geniality (and simplicity) of that
design some years ago, when I opened is and analyzed it.
I seem to remember the paralell port is actually directly connected to the I/O bus or the memory bus or something like that. So that the "CPU" is just halted, and the PC is accessing the flash memory using the same protocol as the "CPU" in the unit would do.

Actually... I'm not even sure there was a CPU/PIC... maybe it just was a "counter" clocking the flash-memory contents into the mpeg-chip...

Marius (Escort Cab + Mark II)