reSIDfp is a fork of Dag Lem's reSID 0.16, a reverse engineered software emulation of the MOS6581/8580 SID (Sound Interface Device). The project was started by Antti S. Lankila in order to improve SID emulation with special focus on the 6581 filter. The codebase has been later on ported to java by Ken Händel within the jsidplay2 project and has seen further work by Antti Lankila. It was then ported back to c++ and integrated with improvements from reSID 1.0 by Leandro Nini. Main differences from reSID: * combined waveforms are emulated by a parametrized model based on samplings from Kevtris; * envelope generator is implemented like in the real machine with a shift register; * high quality resampling is done in two steps to allow computational savings using lower order filters; * part of the calculations are done with floats instead of fixed point; * interpolation is accomplished with Fritsch-Carlson method to preserve monotonicity. reSIDfp is free software. See the file COPYING for copying permission.