Very simple linear congruential PRNG in dasm

lcg.dasm

; Puts "random" numbers in X, Y, and Z
        SET A, 0x1232
        JSR rand
        SET X, A
        JSR rand
        SET Y, A
        JSR rand
        SET Z, A
        SET PC, break

:rand   MUL A, 0x4e6d
        ADD A, 0x3039
        SET PC, POP

; Non-standard, but works in the emulator at http://mappum.github.com/DCPU-16/
:break BRK

A pretty dump little PRNG, that doesn't even use the real LCG algorithm (http://en.wikipedia.org/wiki/Linear_congruential_generator) because it ignores overflow on the MUL, so it's really Xn+1 = (a*Xn (mod 2^16)) + c, which is obviously pretty different than Xn+1 = (a*Xn + c) (mod 2^16).

Next steps: do the algorithm right, seed from keyboard input, maybe create an itoa so that I can print the random numbers, maybe figure out how to store the current seed without assuming it is in A (implies either well-known memory location or some sort of memory management, the former sounds easier, the latter sounds like more fun).