Thanks to the nature of strong programmability, field-programmable gate arrays (FPGAs) have been playing a significant role in signal processing and control. With the explosive growth in digital data, big data analytics becomes an important emerging field, in which FPGAs are a major player. However, the computational speed and power efficiency provided by FPGAs are limited by electronic clock rates and Ohmic losses. To overcome the limitations, photonics is envisioned as an enabling solution, thanks to its ultrafast and low power consumption feature. In this paper, we propose a scalable photonic field-programmable disk array (FPDA) signal processor. Ultra-compact microdisk resonators are leveraged as a fundamental execution units in the core to route, store and process optical signals. By fieldprogramming the processor, diverse circuit topologies can be realized to perform multiple specific signal processing functions including filtering, temporal differentiation, time delay, beamforming, and spectral shaping.