If you simply want to pitch samples the oldschool way, just use any software sampler like Jim Y suggested, export to wav/aiff and then import on the 404SX.
And no, it doesn't take much in terms of processing for pitching samples, it's simply changing playback speed, even the oldest samplers can do that easily - if you aren't talking about pitchshifting or timestreching, of course.

Also a good workaround for pitching down on the 404SX is the DJFX effect. Just set length to maximum (ctrl1 full left) and use "vinyl speed" (ctrl2) for pitching down. You might have to adjust start/endpoints after resampling.

you can do it from a daw like reaper or cubase...

you can do it from an audio editor program like wavosaur or soundforge...

you can do it by recording audio into a more qualified sampler and dubbing back..

But you can't really do it internally in the Sp (without it sounding really bad)

for me, this was the ABSOLUTE worst thing about the sp series...out and out disgraceful IMO. Consider, in this respect, the sk-1 released 20 years ago is more powerful than the sp. It blows me away.

as a stereo sampler the SP also lacks the ability to pan samples in anyway, which is an extraordinary omission.

MC808 can do everything an SP can except accept a 1GB card, and all the other things as well.

I'm more strong on the creative side, rather than technical. So, I stick to hardware as much as possible, but I have Logic 9, and I like what JimY suggested about the instrument sampler idea, though it does not sound like the kind of operation that a DJ would get into.

Personally, for my pitch, I'm starting to think I need some kind of compact tuner in my effects loop chain, because I always have to ask my guitarist what key a song is in, even though I wrote the song. I play by ear, so it would be nice to just have a tuner in my loop, so I could assign it to my backing track channel, get the pitch, then switch it to my tweeking channel and roughly know where I'm going.

The ultimate would be if I could find something smaller than a cassette, that could actually read both pitch AND bpm, with a fair degree of accuracy.

elaborate please

MC 808 is like a 'groovebox' type thing.. synth sounds + sample playing + effects + mixer

I'm unsure but I think you can record unquantized loops despite the design being based around a 16-step sequencer control panel.

stuff like this is probably on purpose though right?

that's why i have some fantasy of a machine like this, but with a cracked/open source os and a big community of users... could be awesome what it might turn into once it's liberated from its proprietary entanglements.

I can recommend the Shareware "AudioRetoucher". You can Play and Pitch MP3s with it and sample directly into your 404.

The Problem with DAWs is: If I start Ableton Live, i end up using it...and then there is no need for me to use the 404 anymore.

So, If I want to use the 404 the computer has to be off.
That´s why I use a turntable, my old Nakamichi-Tapedeck or even a Tracker on the GP2X for pitching audio before sampling.

back in the day we used to use virtual dj for pitching samples or acapellas. its free and it has like +/-20% pitch