it'll never happen, but were i to go about it i would do it like this...

• grab one of the cheap broken random number generators, i'm thinking of the kind that are like 8 bits that cycle through some pattern based on their last value plus they cover all 255 values once and once only before they repeat. so if you had 3 bits and you started at 4 you might get 4,5,3,7,6,2,0,1, and repeat 4,5,3,7,...

• stick together 16 of those 8bit pseudo-random cyclers, seed them all with 0 if you picked different generators for your different bytes, if you used the same generator for all 16 of your bytes you'll have to seed them (and keep track of the seeds) with random numbers.

• run 255 cycles and you have 255 pseudo-random passwords. increment the seed of the last generator and cycle off 255 more passwords. repeat incrementing the seed of the last generator untill it rolls back around to 0 (or the number you seeded it with (don't forget to wrap at 255->0)), then you increment the second cyclic pseudo-random generator and repeat, repeat, repeat.

• eventually you'll get to where your seeds are 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,254 (or maybe 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 if your inital seeds were 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 ) and presto, you've generated every possible 16 byte password in a pseudo-random order without ever doing the same password twice.

• as a bonus you even get the ones with characters that aren't likely to be allowed as passwords for the system (and wouldn't likely be checked by some of those fancier programs).

good luck.

if you happen to find a good 128 bit pseudo-random cyclic generator let us know!