OK Ive got 3 9538a's and 3 9594a's, only two that appear to work to the point of asking for a code
are one 9538awhich however has a dodgy front panel (dodgy push push buttons on pots,m man I love those pots!) and unknown code and one 9594 which is currently displaying SECURITY (or was until I disassembled it earlier). I believe I have the codes for two nonworking 9538's and one nonworking 9594

I have trawled the sleazier edge of the web and finally found a decode program to download but the clarion bit is broken:-(.

I am wondering about swapping out the bit with the code on from a broken but known code one.
None of the chips appear to be socketed as I'd (maybe naively) expect an eprom to be.

Am I on the right track? Which board does the code live on?

Need sounds in the prestige!