The National Radio Astronomy Observatory (NRAO) is launching the Green Bank Ultimate Pulsar Processing
Instrument (GUPPI), a prototype flexible digital signal processor designed for pulsar observations with the Robert C.
Byrd Green Bank Telescope (GBT). GUPPI uses field programmable gate array (FPGA) hardware and design tools
developed by the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of
California, Berkeley. The NRAO has been concurrently developing GUPPI software and hardware using minimal
software resources. The software handles instrument monitor and control, data acquisition, and hardware interfacing.
GUPPI is currently an expert-only spectrometer, but supports future integration with the full GBT production system.
The NRAO was able to take advantage of the unique flexibility of the CASPER FPGA hardware platform, develop
hardware and software in parallel, and build a suite of software tools for monitoring, controlling, and acquiring data with
a new instrument over a short timeline of just a few months. The NRAO interacts regularly with CASPER and its users,
and GUPPI stands as an example of what reconfigurable computing and open-source development can do for radio
astronomy. GUPPI is modular for portability, and the NRAO provides the results of development as an open-source resource.