Calculate your own VISA-Card Numbers - by Martin Fredriksson/MRD! Specially made for Sarcastic Existence! SYNC World Headquarter (C)1992.18.05 - MushRoom Designz The algorithm in this article is specially designed for those creditcards with "4581" in group one. Ex. 4581-0908-2754-6821 _______________________ Group 1 2 3 4 Please note that this algorithm is designed for ALL "4581" cards. This means that there probably aint nobody with credit-group (group2) "9999", but the algorithm will make the correct card-number anyway! So, please watch out what card-numbers you use... I know this proggy is fucking stiff, but it was made on my calculator from B.C. and that aint too good!!! But it shouldn't be too hard to work out the correct algorithm for your computer/calculator. The algorithm works out the last digit in Group4 using all digits in: Group2-3 plus the three first in Group4 UmpaBadiBumpa...Here's the algorithm! :O) ________________________________________________________________________ G = 4 digit-number (group 2) N = 7 digit-number (first digits in group 3 & 4) ________________________________________________________________________ A = ((999999 - 2Int.1G - 10Frac.1G - Int((G+50)/100) - 2Int.001G - Int(G/5000))/10) A = 10FracA B = - 2N - Int ((N+5)/10)-2Int.01N-Int((N+500)/1000)-2Int.0001N - Int.00002N + Int.00001N - 2Int(N/1000000) - Int(N/5000000) C = 10N + 10Frac((99999990+A+B)/10) ________________________________________________________________________ The result in constant C is the complete group 3 & 4 put together. So, the correct VISA-CardNumber would be: Ex. 4581-G-C Good luck and always remember: MushRooms e gottis!