According to the WoS version of the Folklore FAQ, it was Paul Haine who
accidentally misspelled "chutney", and Alan Maxwell who came up with the
definition, to wit:
In the words of the Llama-Waxer himself,
"Spectrums have the one true chuntey, the uber-chuntey if you will.
Other 8-bit machines had similar problems, but paled in comparison to
the Speccy chuntey. Machines such as the CBM64 and the CPC had what
scientists refer to as pseudo-chuntey.
PCs have chuntey-related issues that have descended from these but are
not quite the same - in essence, PCs are affected by neo-chuntey."