I picked up a dual reverb card for my Lexicon PCM 90 but can't use it as my pcm90 has V1.00 ROM and the card requires a unit with the later ROM v1.01.

On the off chance anyone has a PCM 90 v1.01 and wants the extra algorithms and presets shoot me an email.

I looked for one on and off for a couple years before finding this one, paid 160 bucks only to find I'm (as Bugs Bunny would say) "a maroon".

I used to get firmware updates from Lexicon with just a phone call.... have you tried giving them a shout? If the 90 is like the 70 & 80 it should be a fairly simple eprom swap.

Sadly the upgrade kit with the chip is no longer available.
If it was AND I could do the upgrade myself I'd be all over it.

I've a couple of bud's with eprom burners... if you track down an image file of the eprom I could ask them to burn one.

Sounds illegal, but should be kosher with Lexicon's blessing