What are the major technical difference between Multics and Unix . . . Another significant difference between Multics and Unix was the size of the virtual memory accessible to a process It is true that each Multics segment was limited to 255K 36-bit words in length But each process mapped more than 300 such segments into its address space
When was the term Multics (operating system) coined and by whom? The history of Multics is interesting because the failure of its development led to the development of Unix which is now used in the form of BSD and macOS iOS and further we have widely used Unix-like operating systems e g GNU+Linux But from the history of Multics, I couldn't find any information about who had coined the term Multics and when
emulation - Are there runnable Multics systems available . . . The notion that Multics was a failed precursor to UNIX is most fictitious Mostly, AT T worked on MULTICS for a while, and then decided to pull out of the project I guess from the AT T perspective, that qualified it as a "failure", but in fact others continued and finished the project, and it continued to be used for quite a long time (decades)
multics - Why did Unix use slash as the directory separator . . . The Unix designers came from the GE MIT Multics project, and Multics inspired some Unix features In particular, Multics has a hierarchical filesystem, and so does Unix On Multics, pathnames were of the form: >dir1>dir2>dir3>filename but Unix uses dir1 dir2 dir3 filename
What is the difference between CTSS and ITS? The "Incompatible" in ITS was a humorous reference to the "Compatible" in CTSS For comparison purposes, the name unix was chosen as a deliberate ironic reference to the "multi" in Multics While the people who built ITS would have called themselves "hackers", this can be misleading in today's context
multics - First operating system with system calls - Retrocomputing . . . @dave I love that It is the most essential operation proving the existence of a monitor software (or OS) Thus any system that shows program chaining (batch job(s)) without the chaining code being part of the user program itself would qualify as OS by above rules :)) In the end it shows that, as so often, those questions about 'firsts' are all depending on chosen attributes and thus usually
history - What methods were used for password encryption before . . . The Multics scrambler works by first compressing the 8 Multics-ASCII character password from 72 to 56 bits by removing the high-order two bits (always zero in the 9 bit Multics representation of 7 bit ASCII characters) from each character If the password is less than 8 characters in length, blanks were added to make it 8 characters long
When did Multics begin using gt; as a pathname separator? However, an early paper describing the implementation of the Multics filesystem uses : instead (and provides no indication of how parent directories were referenced) My understanding is that this paper describes the state of the Multics implementation as of "phase 0 5", which was a simulation of components of Multics running under an emulator
Why did so many OS names end in x? Multics was meant to be many things; reliable, available, meant to support multiple layers of security, meant to support many users, meant to support hot-swapping of system components It required "big iron" hardware, it was bloated, it was over-buget, and it was late
How did Multics make library calls available as shell commands? In Multics, when the command processor calls out to a program the system linker finds the right entry point in the file system and links it into the process right then and there and an actual machine-instruction call is made, just as if it had all been compiled together That command becomes "part" of the shell (in the modern view, of shared