History Archive

      ROM CARD and ROM CHIP DEVELOPMENT
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On this page, you will find photos and info on the development of the Rom chips and the PCB expansion card.

Many years ago KORG   and METRASOUND used to sell ROM cards for the DDD series of drum machines,but these have been long discontinued and are now very rare.

 

The KORG DDD1 and DDD5 were some of the best drum machines made in the 1980's

and it seemed a shame that it was no longer easily expandable.

The idea was to add new sounds to the DDD series and expand it's usefulness in modern  music production.

   

     

Rom card fitted in DDD-1

 

Rom card fitted in DDD-5

 

Rom card in slot3 of DDD1

 ROM card in DDD5 slot1

The Picture BELOW shows the hand made prototype  PCB ,designed

to simply slot into the DDD drum machines, eliminating 

any need for opening up the DDD machine.

It works just the same as a "normal" ROM card.

So far it works OK with a  UV erasable EPROM

Here, the TR909 ROM is mounted on the PCB.

a very roughly made PCB , but it works very well

 The rom chip contains a couple of snares and kicks, 2 hi hats and a clap sample.

This is now added to the TR909 ROM and the "Beatbox "  ROM already done.

So far all the testing has been done using  a Chip socket mounted on some VERO BOARD

which is wired into the main PCB on the DDD1, the Vero board sits in the space

where the battery for the sampling PCB would go.

We chose this method as its the most convenient way of testing and inserting /removing chips

without having to open up the DDD1 all the time.

The picture below shows the TR909 Chip in place on the Prototype "test" board

The idea to make this into a "kit" was abandoned because it was  difficult to fit the  board to the main board inside the DDD1
this was mainly used for testing the rom chips , before the PCB was made.

After the chips were tested and working the PCB was next:

" Now we have to concentrate on the PCB, and  that is going to be tricky

and we want to get  right,  also we're not sure how a pcb is going to hold up

to being pushed in and pulled out of the card slots all the time,

(a bit like the old Commodore 64 and VIC20 cartridges in the 80's)..."

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