The Yamaha D1500 is a digital delay system with a time range of 0 to 1023 milliseconds in 1 millisecond increments, with full 20Hz to 18kHz frequency response throughout the delay range. It was the first commercially available digital delay with a MIDI interface and follows the success of the R1000 digital reverb.
Any of the D1500's 16 programmable memory banks can be selected remotely from a MIDI instrument. This allows specific delay effects to be assigned to particular instrument voices. The appropriate delays are then recalled automatically as each voice is selected.
This is all working and sounds great for the vintage digital delay thing