2020年7月20日 · 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 …

2018年7月6日 · 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).

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

2020年7月5日 · 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.

2019年4月20日 · 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.

2024年7月13日 · @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 …

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 ...

2022年12月31日 · 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 ...

2024年3月5日 · 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.

2025年1月31日 · 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 …