sciwise, do you really use Winfract 18.21? It's very old (anything before version 19.6 is more or less "stone age territory"). There's an updated version here (I can't reach www.fractint.org at the moment): http://twegner.dyndns.org/fractint/ftp/current/windows/winfract-20.04p09.zip Cut and pasted from Winfract 20.04patch9 Help: --------------------------------------------------------------------------------------------------------- This release of Winfract is essentially the same as the version 18.2 but with the following enhancements: - All fractal types from Fractint 20.4 (with the exception of the 'julia_inverse' fractal type, which requires some extra logic we haven't yet added to Winfract) have been incorporated into this version of Winfract. - The File Open, File SaveAs, and File Print options now use the new Windows-style "common dialog boxes", with the extra capabilities provided by those routines. This is particularly handy if you're using Windows-for-Workgroups or Windows NT, 2000, XP with their networking options. - The fractal history feature of FFD has been implemented and uses the h key to move back in history and the H key to move forward in history. --------------------------------------------------------------------------------------------------------- I hope you excuse me from scrambling your code (not all of it was necessary, but is the result of trying to get it to display something on my machine. Note that the inclusion of formulas in .par sets works only from version 19.6 on, if my memory serves me right. Regards, Gerald ---------------- .PAR SET BELOW ------------------------------------ Diode { reset=2004 type=formula formulafile=fractint.frm formulaname=LnDioGH corners=-0.16588419/0.25978091/-0.15031315/0.1691023 float=y maxiter=512 logmap=yes periodicity=no colors=00000j0j0jj0j00j0j0jjkkkkrkdmwW000W0WW000WW0W0WWFNF<5>zNFFVF<5>zV\ FFbF<5>zbFFjF<5>zjFFrF<5>zrFFzF<5>zzFFFN<5>zFNFNN<5>zNNFVN<5>zVNFbN<5>zb\ NFjN<5>zjNFrN<5>zrNFzN<5>zzNFFV<5>zFVFNV<5>zNVFVV<5>zVVFbV<5>zbVFjV<5>zj\ VFrV<5>zrVFzV<5>zzVFFb<5>zFbFNb<5>zNbFVb<5>zVbFbb<5>zbbFjb<5>zjbFrb<5>zr\ bFzb<5>zzbFFj<5>zFjFNj<5>zNjFVj<5>zVjFbj<5>zbjFjj<5>zjjFrj<4>rrjzywccdWW\ Wz000z0zz000zz0z0zzzzz } frm:LnDioGH{ ; ; Complex Voltage - Complex Current ; Diode Characteristics . ; ; for 1N4148 silicon type . ; Level 1 model . ; ; at 25 degrees C ; Pd = 0.0000000000001 Gm = 0.00000000000094 Ids = 0.00000000252 Rs = 0.968 n = 1.752 Vt = 0.025 u = Gm*n*Rs*Vt+n*Vt Pt = n*Vt vr = Ids*Rs x = 0.1 x = x-((u*x*log(x)+vr*x*x-(Pixel+vr)*x)/(vr*x+u)) z = 0-(Pt*log(x)-Pixel)/Rs: u = z x = x-((u*x*log(x)+vr*x*x-(Pixel+vr)*x)/(vr*x+u)) z = 0-(Pt*log(x)-Pixel)/Rs |u-z| > Pd } -------------- END OF .PAR SET ------------------------------------------