GPC uses a more elaborate pseudo random number generator than BP does. Using the Random and Randomize functions works the same way, but there is no RandSeed variable (but a SeedRandom procedure). However, if you use the System unit (see - -uses=System - Swap; HeapError; etc.) and define the symbol __BP_RANDOM__ (by giving -D__BP_RANDOM__ on the command line), it will provide a 100% BP compatible pseudo random number generator, including the RandSeed variable, which will produce exactly the same sequence of pseudo random numbers that BP's pseudo random number generator does. Even the Randomize function will then behave exactly like in BP.