Z:gnu-www-ja-stallman-kth--fdb56c-In the real old days our hacke/en

In the real old days our hackers used to modify the machines that came from Digital also. For example, they built paging-boxes to put on the PDP-10's. Nowadays I think there are some people here [in Stockholm] who do such things too, but it was a pretty unusual thing in those days. And the really old days, the beginning of the 1960's people used to modify computers adding all sorts of new instructions and new fancy timesharing features, so that the PDP-1 at MIT by the time it was retired in the mid-seventies had something like twice as many instructions as it had when it was delivered by Digital in the early sixties, and it had special hardware scheduler assisting features and strange memory-mapping features making it possible to assign individual hardware devices to particular timesharing jobs and lots of things that I hardly really know about. I think they also built in some kind of extended addressing modes they added index registers and indirect addressing, and they turned it essentially from a weak machine into a semi-reasonable one.