Eml synthesizers

>With EML's gear I
>guess pre-500 or 400, playing standard equal tempered
>material was possible but not exactly the quickest or easiest
>thing to do either IMHO - Which brings up the 400 - was it easy to
>play standard tuning on that combo and conversely, was it also
>easy not to?
The synth side of the 400 sequencer is clearly  related to the 500. The 
synth control layouts are nearly identical. The 500 adds a few features but 
it's close enough that I think it's safe to assume that  the basic synth 
architecture was probably the same. I would guess that they just took a 
400  synth design and adapted it to work with a keyboard to create the 500. 
In any case, they both have a
quantize/scale slider and it works the same way.