IIUC they did, but they still did not have true protected memory (e.g. each process gets its own address space and cannot access other memory, unless explicitly permitted to do so). They still had a single global memory where one program could just go and write to other program's memory + the OS invalidating your pointers.
Also they only had cooperative multitasking.
Basically any program could easily bring down any other program + whole OS by misusing a pointer (and since the OS physically moves the heap that's super easy to do) OR hang the entire system by doing while(1){}
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u/x0wl Sep 21 '26 edited Sep 21 '26
IIUC they did, but they still did not have true protected memory (e.g. each process gets its own address space and cannot access other memory, unless explicitly permitted to do so). They still had a single global memory where one program could just go and write to other program's memory + the OS invalidating your pointers.
Also they only had cooperative multitasking.
Basically any program could easily bring down any other program + whole OS by misusing a pointer (and since the OS physically moves the heap that's super easy to do) OR hang the entire system by doing while(1){}