;*************************************************************** ; ; A stereo reverb for the DSP56001 signal processor. Based on, ; ; Moorer, James A. "About This Reverberation Business." ; Computer Music Journal Vol 3, No. 2 (1979), pp. 13-28. ; ; reprinted in, ; ; Roads, Curtis, and Strawn, John, ed., _Foundations ; of Computer Music_, pp. 605-639, MIT Press, 1985. ; ISBN 0-262-68051-3 (paper) ; ISBN 0-262-181142 (hard) ; ; Each comb filter uses a low-pass filter in the feedback path. ; The combs and all-pass filter delay lines use a prime-number ; of stages to improve diffusion. ; ; The output all-pass stage is replicated for left/right ; decorrelation. Each side uses slightly different gains ; and delay lengths. This works a lot better than just inverting ; one side and adding in the input. ; ; I left out the early-reflection FIR filter because I needed the cycles ; for other effects. ; ; Quinn Jensen (jensenq@qcj.icon.com) ; ;*************************************************************** psect vectors p:$0000:$0040 psect hf_code p:$0040:$0200 psect hf_datax x:$0000:$0040 psect hf_datax1 x:$0040:$0100 psect hf_datay y:$0000:$0040 psect hf_datay1 y:$0040:$0100 psect midi_data x:$0400:$1000 psect lo_data x:$1000:$F000 psect lo_code p:$F000:$FE00 psect loader p:$FE00:$FFFF psect iox x:$FFC0:$FFFF psect ioy y:$FFC0:$FFFF ; ; some oft-used constants ; psect hf_datax ffff dc $FFFF ;used a lot for modulus ONE equ $7FFFFF ;"one" one dc ONE ;"one" ; ; L/R inputs and outputs ; in_l dc 0.0 in_r dc 0.0 out_l dc 0.0 out_r dc 0.0 ; ; recompute comb gains g1 and g2 ; recalc_comb_gains move x: