I'm sure we'd all appreciate a list of machines that people have found to be unbendable, or if they are bendable are fairly useless. Make your nominations in this thread and add a little bit of detail if you wish although i wouldn't trust this list 100%. Just because someone hasn't managed to bend something doesn't mean its not possible. I'll edit this thread down to a couple of posts every now and then if this topic works out.
UNBENDABLE MACHINES:
Yamaha VSS-100: The sampling side can't be bent with any real success unless you just want a shitload of noise. Never tried the synth side. (circuitbenders)
Korg DDM220 / DDM110: Very difficult without much reward. (circuitbenders)
Speak&Music: Never found anything worthwhile on the UK version although the US and french versions may be different. (circuitbenders)
Casiotone mt-55: isn't particularly great either. There's bits there, but nothing outstanding. (Signal;Noise)
Yamaha PSS16: one chip wonder. (catweazle)
Bontempi Electronic Mini Keyboard B20(catweazle)
Yamaha PSS-12: A few bends which alter the voices somewhat but nothing spectacular. I have heard better reports for PSS-6 although I believe that is just a mono version of the PSS-12. (iqoruvuc)
Super Speak&Spell 1991 and Super Speak&Math 1991: both are nearly unbendable. (catweazle)
Yamaha RX-11 / RX-15: apart from a couple of weak distortions theres just a whole lot of connnections that lock up, reset and crash the machine. Major pain in the ass. (circuitbenders)
Yamaha PSS-30: One of the most unbendable chips ever (someone on this forum)
yamaha pss-50/pss-9 - these models are exactly the same with slightly different markings and model numbers. they solidly withstand any attempts to bend. gits... yamaha, what were you thinking? (andy wheels)
bontempi '666' range - evil italian unbendableness and easy to fry too. ugh. (andy wheels)
Cheetah MD8 - The most Volatile Non-Volatile memory you'll ever encounter. You have to load the sounds in from tape which never works and its so prone to crashing it even has a factory installed hard reset button! (circuitbenders)
Yamaha PSS-50 - Only one chip so no seperate fm chip to cut datalines from! Nothing interesting. Real dissappointment!(iqoruvuc)
Yamaha PSS-80 - totally dissapointed with what I got from it. Probably the worst bend I have done so far!(creature)
Pre-school Musini - That wasn't much fun. The normal version has a lot more potential appearantly, but I didn't know any difference when I bought this one.(iqoruvuc)
Bontempi 4400 - not interesting, doesn't smell nice inside either(nochtanseenspecht)
Finger Beats Finger Mixer - This one is constructed to well, i had no luck with bending this what so ever. (davinyljunky)
Mekie 373D37 Key Kids Keyboard - This is cheap china manufacturing at it's worst. Don't even waste your time on this one, it's cheap and nasty. (davinyljunky)
Machines Badged as Leapfrog - Probably doesn't apply to all of them but i've had a few machines made by Leapfrog and mysteriously none of them were bendable (circuitbenders)
TI MAths Marvel - i cant find any bends what so ever (matt the modulator) Same here (circuitbenders)
Fisher Price "Tune In TV" , Sesame Street version - It's got some kind of automatic reset that I can't bypass and pretty much ignores any bending attempts (egr)