The Alesis HR-16 was an inexpensive, easy-to-use MIDI drum machine from the early ’90s. [Burnkit2600] had a lot of experience circuit bending the HR-16 and decided to burn some custom sound ROMs for it. The HR-16 has two 32-pin ROMs that are conveniently socketed. He pulled the chips and dumped the image using an EPROM reader/writer. The ROM only contains sound samples, so you can open it up in raw mode using a program like Sound Forge. The samples are separated by short negative regions. All you need to do is place your new samples between the pits and burn a new ROM. You can piggy back the chips using the chip enable line to add even more samples.