Vintage Simmons Drums (UK) Users Group

Hi,

Does anybody know what the four-prommed SDS7 cards are used for? Are 
the sounds selectable like on a Simmons SDS1000, or are they parts of 
sounds on separate chips like on rival machines such as the LinnDrum, 
Oberheim DMX, or Sequential Circuits Drumtraks. I found a Simmons SDS7 
tom card on eBay today and just wondered that. I know that it has 
the "Townhouse Tom", "Gated Tom", "Conga 1", and "Conga 2" EPROMS 
installed on an expansion card that is mounted where the single EPROM 
goes on a digital-analog SDS7 card. The expansion board is not 
something made or installed by a third-party user because it 
said "Simmons Group Centre" on the expander board. I have not seen this 
before. I have only seen the digital-analog card that holds one EPROM 
and the digital card that holds two EPROMs. Can anyone tell me what the 
four-prom cards are for?

Thanks for your help

Dean Rumsey