4 ms·

The PDP-11 had 16k.

• retrac 7y ago
  Yes, the original PDP-11/20 came with as little as 8 KB of RAM. But early operating systems and languages for the PDP-11 were painfully primitive. We're talking paper tape and assembly only, in 1970 on the base 8 KB of RAM. On the other hand, consider the memory requirements of UNIX v7. It required separate instruction and data address spaces using the PDP-11's virtual memory features, as neither the kernel nor some of the compilers would fit into only 64 KB of data/code. 128 KB was necessary to boot a minimal single user system. 256 KB was realistically required to run multiple processes. By 1979, that's software requiring 16x as much memory as in the base configuration of the original PDP-11 of 1970, just to boot. It just would not have been possible to write something like v7 UNIX in only 16 KB of RAM.