Audio Realism bassline… Its about to hit 3.0… Its expensive though. 95 euro. There are a tons of Synth Edit 303’s around… There is a Native Renoise 303… but its not a tool yet… and I have trouble figuring out what direction Bit-Arts is taking this in
I would love to see this as a tool!
Here is a free VST worth a try, open303. It lacks a fancy GUI and internal sequencer like ABL and others, but you’ll just automate the parameters like everything else.
However, the native one mentioned above sounds great.
TS, study this thing well and you’ll know how to create any sound yourself 
also try custom wave tool and perhaps my new tool ‘overtune’ to check out how different oscs/chiptunes sound. use lofimat. use the moog lpf. automate. bind a velocity tracker (max 0) to a lfo’s reset which has “one shot”. use hydras.
I see! Lol. Ok, but Mr. Bit-Arts seems to be redoing his website, so I will have to wait, till he fixes, or replaces the link to the project file.
I had the project file, but I have been setting up a new PC, and I’ve had to do a lot of uninstalling, and reinstalling, and all kinds of tweaking, that the project file to this 303 got lost in the mix… 
But I will a quick forum search for your overtune.
i like the one by computer music magazine, cm-303.
He’s not redoing his website, afaik. He has deliberately taken all of his Renoise links offline.
He got quite angry during a recent thread, and then decided to quit the forum (for the second time) and take all of his files offline.
I personally think he takes such trivial comments far too seriously, but, go figure.
^ This.
VB-303 (Venom Bassline) is a free one with a terrible GUI, but a very close emulation of both the sound and the sequencer. Pretty hard to work with so just plan on relying on the “random” button for ideas. It’s still under development, so hopefully it will be improved soon. Worth a shot though…
Quick edit: I think there’s an updated d/l link further in the thread, but I’m not positive (somewhere around pg 20 is in my mind for some reason, but don’t quote me.)
i was going to say Phoscyon. Got beaten
Yep, this. Excellent price/performance ratio. I can only recommend it.
Thanks all, some great recommendations there. I do like the look of that phoscyon, bonus that it has an arpeggiator too. Will check out the demo version and see what I think.
I took a look at open-303 but would prefer something with a nice gui.
That AudioRealism bassline is a bit pricey, even phoscyon looks expensive when you compare it to the purchase price of renoise itself. I’ve not paid out or a vst yet as there’s so many great free ones out there but I think I would do for a good 303-a-like as it’s such a specific sound you’re looking for.
Phoscyon is definitely my favorite. The chord shape arpeggiator rules.
http://soundcloud.com/wahrk/nicholas-j-cumberbund
Edit: The above track was made using it, if that wasn’t obvious.
It’s a fairly basic sound, anything with square/saw waveform and a filter envelope can get pretty close.
VSTi-wise, my pers. list of “most authentic emulation” looks like:
I bought SilverBox when Spectralhead Audio was still alive - unfortunately the little company died a couple of days after i bought it (hope there is no relation to my purchaseg), but maybe you can manage to your hands on it somehow…
at least, there is a video on the tube where you can take a look at it:
and even though i respect the project for being free and open source and what not, but open303 is really, really far away from sounding anything like a 303 imo.
FF Twin2 and NI Massive actually make some pretty good acid sounds, they both have really nice analog sounding filters. Massive even has a filter called “acid”. lol
MounTau2
Hate to come in late to the party, but I thought for future forum searchers I’d leave this here:
http://www.g-sonique.com/alien303.html
It’s on sale this Summer, too. Got mine for just under $13 USD.
It has a lot of presets, and can be made to lead or bassline depending on how you use it. It’s a bit thin sounding in some of the patches, to be honest, but a little bit of (the free VST) Density MkIII and it just siiiiings. 
you know, all Bit_Arts’ solution really needed was one crappy saw sample and some LFOs, Hydras, Filters and Distortion! 
I’ll try and recreate a little bit of how he did it by what I remembered from it
here you go: something-sawwy 
There is only one real solution: TS404 by Image Line