Right now, the number one most requested feature for LittleGPTracker is MIDI output from the PSP port. It'll probably happen at some point in the future, but right now it's not. But if you've got an old drum machine or hardware sequencer that supports "Tape Sync", you can slave it to your PSP today! What's more, you don't need any sort of interface - just an audio cable. Many classic Roland drum machines support Tape Sync, and apparently it also turned up on machines by Linn, Sequential, Yamaha, Korg and Oberheim.
Using the method below, I've successfully slaved my Roland TR-707 (aka The Instant Chicago House Machine) to my PSP. The sync works, and it's tight. The wonderful thing about the 707 is that it's a jack of all trades when it comes to syncing - as well as receiving Tape Sync, it'll spit out DIN sync *and* MIDI. I haven't tested it with any further devices yet, but in theory you should be able to slave a whole chain of grooveboxes and sequences to the PSP using a 707 as an interface!
I got my info about Tape Sync here:
http://www.adambaby.com/studiotech_sync.html
In a nutshell, the Tape Sync signal is an audio pulse that, when fed into the 707, translates into clock info. So what we're going to do is split the stereo output of the PSP into two mono channels. Down one, we'll send a Tape Sync signal to the 707. Down the other, we'll send all our instruments. The disadvantage of this is that all your Piggy sounds will be mono and you won't be able to use any panning, but that's a small price to pay!
Here's what you need to do.
1. Start by creating a new chain, and within that create a new pattern.
2. Set the global groove (i.e. "Groove 00") to 0C/0C (the default is 06/06).
3. Set the overall tempo of the song to DOUBLE what you want it to be. So if you're writing a song at 120BPM, set the tempo to 240.
4. Go to your empty phrase. On every step of the phrase, insert the note D6 using a fresh, new instrument.
5. Go to the instrument settings. For the sample, you'll need a single cycle 50% duty squarewave - as we're chip musicians, everyone should have one of these! I used an old NES sample. Set the root note to C4, set the panning all the way to FE (hard right) and set the loop mode to Oscillator. Set automation to false, and set the table number to a new, empty table.
6. Go into the table you've just set. On the first twelve steps (i.e. 00 to 0B) put a PTCH command (you can leave the last four steps blank). For the values, alternate each step between 000C and 0000, so that steps 00, 02, 04 etc. are all 000C, and steps 01, 03, 05 etc. are all 0000.
7. That's it! The pattern you've created is your Tape Sync signal. Make sure you don't put anything else on this channel - this pattern has got to be playing for the full length of the song. If it stops, your Roland will stop receiving a signal and will go out of sync.
8. All your other Piggy instruments should be panned to 00 (hard left) on the instrument screen. Any that aren't (a) won't be heard and (b) could disrupt the sync signal.
9. Plug 3.5mm stereo to 2 x mono into the PSP headphone socket. The right channel jack needs to go into the Roland tape sync socket. On the 707, this is a 3.5mm mono jack, so I had to use a phono-to-3.5mm mono adapter. Plug the left channel jack into your mixer / amp / whatever.
10. On your Roland device, you need to set it to listen for Tape Sync. This is basically the same principle (and I believe protocol!) as slaving an LSDJ unit - you set it to slave, press start and then it waits for a sync signal before starting. On the 707, you need to tap the Track button, then hold down Shift and press the Sync Mode button until the LCD display says "S-t". Then press the Pattern button to enter Pattern Play mode, select which pattern you want to play and hit Start. The LED for step 1 should be lit along with the LED for whichever pattern you've chosen.
11. Press Start on your PSP. If all's well, your Roland should start and be playing tightly in sync with your PSP! Then, spend the rest of the day writing jacking Chicago house tunes.
Obviously when you're dealing with gear (and a sync protocol) this old, there will be quirks. I've found a couple with the 707. Most importantly, when it stops receiving a tape signal, the 707 switches back to its default internal clock, meaning you need to reset it by hitting stop, then going back into Tape Sync mode (which is about half a dozen button presses). This is unavoidable between songs, but could be disastrous mid-song, so you need to make sure that the sync signal is playing ALL THE TIME during your song - if you don't want to hear the drums, flip to an empty pattern on the 707 rather than muting or stopping the sync signal.
Secondly, I noticed a couple of occasions where Piggy and the 707 started in sync but weren't totally aligned. This didn't seem to happen if I wiggled the tempo knob on the 707 a little before entering Tape Sync mode. I don't really know why this worked, and it might not work every time; it could be that fiddling the tempo helps it 'forget' the tempo it was running at previously - but this is just guesswork (the 707's internal clock is very solid, but the BPM settings aren't).
Here's a REALLY TERRIBLE demo that I wrote in 20 seconds to show the 707 and PSP in perfect sync. The music's awful, but it proves the point:
http://www.giantmonster.co.uk/misc/piggysync.mp3
Anyway, it's not exactly the dream PSP sync solution as you need an old Tape Sync device to use it, but if you've got one it's pretty tight. I'd love to know if anyone makes use of this!
Matt
