Can't understand what's happening here.. I have the impression I met a similar behavior already but I'm not sure. Using the 'stable' z80asm version does not solve. Ideas ? C:\z88dk\examples\graphics>zcc +zx mandel.c cp /cygdrive/c/z88dk/lib/spec_crt0.opt /tmp/tmpQzM67Yna.opt cp /tmp/tmpQzM67Yna.opt /tmp/tmpQzM67Yna.asm zcpp -I. -DZ80 -DSMALL_C -DSPECTRUM -D__SPECTRUM__ -DSCCZ80 -I/cygdrive/c/z88dk/ include mandel.c /tmp/tmpuptJMuN9.i sccz80 /tmp/tmpuptJMuN9.i copt /cygdrive/c/z88dk/lib/z80rules.2 < /tmp/tmpuptJMuN9.asm > /tmp/tmpuptJMuN9. op1 copt /cygdrive/c/z88dk/lib/z80rules.1 < /tmp/tmpuptJMuN9.op1 > /tmp/tmpuptJMuN9. opt z80asm -eopt -ns -Mo -I/cygdrive/c/z88dk/lib /tmp/tmpuptJMuN9.opt z80asm -a -m -Mo -L/cygdrive/c/z88dk/lib/clibs -I/cygdrive/c/z88dk/lib -oa.bin - izx_clib -iz80_crt0 /tmp/tmpQzM67Yna.opt /tmp/tmpuptJMuN9.o Error at file 'zcc_opt.def' line 8: Symbol 'NEED_FLOATPACK' already defined 1 errors occurred during assembly Key to filenames: /tmp/tmpuptJMuN9.o = mandel.c Error at file 'zcc_opt.def' line 8: Symbol 'NEED_FLOATPACK' already defined ^ ---- DEFINE NEED_floatpack