Hi M.A.F.... Shame on you for not knowing what ST-01 is... go to the back of the class
As Komet64 says ST-01 was the

FIRST

and by far most celibrated official instrument/sample disk for use with Sound Tracker on the Amiga. It was bundled with the

FIRST

Soundtracker package devised by Karsten Obarski called Ultimate Soundtracker released by Electronic Arts in 1987. What is currently unclear is exactly -who- produced the first batch of samples as there apear to be no credits in the original documentation. It is possible that Karsten himself produced the first samples although I have a hunch that the first disk may have been produced by more than one synth owner. What is also not clear is how the first first song disk came about - obviously several of Karsten's songs are on there but how the rest were collected I'm not sure.
I'm interested you have a Poly-800 - I'd either be interested in helping you replace the backup battery and factory presets or even purchasing it off you if you are interested.
Yes - I agree the Poly-800 isn't totally fantastic but like so many older synths - it has it's place doing specific tasks. Actually I'd make a warning to anyone tempted to purchase some of the synths used to make ST-01. There is no doubting that the Roland D-50 and JUNO-106 are lovely synths with plenty of years left in them but both will cost you a fair amount of money thesedays as they are collectible. The Juno is beautifully programmable but to really get to the D-50s power you need a PG1000 and this & a D-50 costs more than a Juno. The DX100/21 on the other hand is a very poor example of 4 OP FM - if you want the best sounding FM synth that can play back the DX100 presets directly then get a TX81Z - it's the professional rackmounted version designed to be backward compatible with all of the Yamaha 4OP synths and it's got much quieter DACs on it - it also fully responds to velocity, aftertouch and breath control. It's cheap and built like a tank - see Ebay! The TX81Z is most famous for it's preset "LatelyBass" - a dance/pop bass still used to this day. This bass is called SolidBass on the DX100 - I don't know why it's name was changed. I'm almost 100% certain SolidBass is present in at least two ST-01 samples.
Another question for all you budding Amiga fans - which 8 bit hardware sampler upgrades & sampling packages were popular/available on the Amiga in 1987?
Dan.