(As an old time B6700 hack ...) I think there were two main architectural problems with the Burroughs architecture: - it depended on compilers making safe code

(As an old time B6700 hack ...) I think there were two main architectural problems with the Burroughs architecture: - it depended on compilers making safe code for both its system security and system integrity - this mean that you couldn't write your own compiler without being the equivalent of root, and you couldn't test it without potentially taking down the system - there was no hard memory protection between processes -memory descriptors contained both lengths and pointers - that limited memory size to 2^^((wordsize-overhead)/2) words - in Burroughs case it was 6Mb (6 byte words) huge at the time, tiny today The 432 had it's own issues - I think it designed itself into a corner at a time when memory speeds were very low so tight instruction coding was important, microcode was where you got your speed - the problem with that is of course that buggy microcode is hard to fix - cheaper/faster memory made the risc revolution possible and now we look at different bottlenecks