The Roland D-110 is a Linear Arithmetic (LA) synthesizer released in the late 1980's. At the time, sound ROM was very expensive and of limited capacity. In order to save space and still be able to generate complex sounds, Roland designed a line of synthesizers based on building sounds from two components - attack transients and sustain waveforms. A more complex attack waveform representing the pluck of a string could be combined with a fairly simple sustain waveform to create a realistic instrument sound while using very little memory compared to storing the full waveform. This approach also gave more flexibility in combining sounds.
The D-110 was part of the second generation of LA synthesizers that included the D-5, D-10, and D-20 keyboards. They were the follow-up to the first-generation D-50 and D-550 synths.
To play the internal ROM demo, hold down the ENTER button and push the edit button. Pushing the enter button again causes the 8 built-in songs to play. Though they're pretty cheesy, they're a great way to test the unit.
It uses a standard CR2032 battery for patch memory. This battery is not optional, so if your D-110 is behaving strangely, replacing this battery is one of the first things to try.
The D-110 has 3 internal circuit boards. These are the main board, marked "ASSY 7954410 00", the analog board, marked "ASSY 79454420 00", and the power supply board, marked "ASSY 795454440 00".