The Roland digital drums system consists of the DDR-30 digital drums module
and two kinds of dynamic pads.

Basic sounds of the DDR30 are PCM recorded bass, snare and 4 toms (each with
4 different PCM digital sounds). Up to 8 kinds of modified preset sounds per
voice can be stored in internal memory and 64 more on ram cartridge. Midi in, out
& thru connectors are provided as well as individual and mix outputs. list price for
DDR-30 digital drum module $1195.00

PD-10 MIDI BASS DRUM PAD $195.00
PD-20 MIDI SNARE OR TOM PAD $99.00
(COMPLETE SYSTEM W/ 6 PADS & MODULE) $1885.00

From 1985 Roland new product news.

The new Roland's Digital Drum System consists of the
DDR-30 Digital Drum Module and two kinds of drum pads designed exclusively for use with the DDR-30-the PD-10
Bass Drum Pad and the PD-20 Snare DrumlTom Pad.
Realistic digital sound sources, flexible sound modification,
MIDI compatibility, and superb playability draw distinction between the system and others.
The DDR-30 has six drum voices-Bass Drum, Snare Drum, and four Toms. Four different PCM digital sounds are provided for each voice. The Edit function allows the preset sound to be freely modified over 13 parameters, such as the Voice, Pitch, Attack, or EQ. It is also possible to store the modified sound in the DDR-30's memory up to 8 kinds per voice. In addition, the DDR-30 can memorize 32 combinations of the sound of each voice-especially effective for live performance.
The DDR-30 is touch sensitive. Not only the loudness, but also the tone and the attack faithfully changes according to the drummer's hittin3 force.
AlG-digit display indicates the patch number and program number. It also spells out the parameter name when it is modified for easy, accurate sound modification.
Featuring the MIDI In and Out jacks, the DDR-30 can also be used as a drum sound source for a MIDI sending unit.
These attractive features are packed within a rackmountable EIA-2U package. The DDR-30 can be mounted on a rack with other rack-mountable units required, such as an effector or amplifier to form a sophisticated set-up.
The PD-IO Bass Drum Pad and the PD-20 Snare Druml Tom Pad give the drummer natural elasticity and bounce, because the hitting surface of each pad consists of three layers of particle board, rubber, and film.

DDR-30 SPECIFICATIONS
Sound Combinations: 32 (8 combinations x 4 banks)
Sensitivity Controls: Bass Drum, Snate Drum,
Tom 1, Tom 2, Tom 3, Tom 4
Voice Selectors: Bass Drum, Snare Drum, Tom 1, Tom 2,
Tom 3, Tom 4, Program Number
.Editors (Parameters): Voice (Voice Number, Amplitude, Decay.
Gate Level, Gate Time, Release), Pitch (Pitch,
Bend Depth, Bend Time, Dynamic Sense),
Attack (Attack), Equalizer (Bass, Treble)
Rotary Encoder: Data Entry
Switches: Edit Write, Patch Write, MIDI
Pad Trig In Jacks: Bass Drum, Snare Drum,
Tom 1, Tom 2, Tom 3, Tom 4
Multi Output Jacks: Bass Drum, Snare Drum,
Tom l,Tom 2, Tom 3, Tom 4
Master Output Jacks: R (R + L), L
Remote Control Jacks (use DP-2): Bank Shift, Patch Shift
MIDI Jacks: In, Out, Thru
Dimensions: 483(W)x 88(H)x 300(D)mm (19.0" x 3.5" x 11.8"),
Rack-mountable EIA-2U
Accessories: Connection cord x 2