dash as switches were always explained to me as from Multics. Having used DEC systems, Univax and IBM systems originally with cards and ASR33s, I was not yet stubborn enough to see value one way or the other (the links in ROMs in my fingers were not yet programmed). By the time I left CMU and the glass tty was all I was willing to use. I had become a UNIX/C person more than anything else, so slashes as switches (and upper case and case folding) had become annoying and just seemed wrong. On Tue, Nov 28, 2017 at 8:19 AM, Noel Chiappa &lt;jnc(a)mercury.lcs.mit.edu&gt; wrote: ​That was the impression I had had and I admit I think I must have either assumed it, heard it in conversation, or maybe read it at some point in this paper. Cann't say when I started to think same, but I came to UNIX in Fifth and Sixth so, they were already there. I was just learning the 'UNIX way' at the time.​ I guess because I was using so many different systems at the time, I was more willing to accept every dialect had its way of doing things. As Greg points out EXEC-8 was hardly anything like TSS/360 and learned them together. Same as TOPS/TWINEX and eventually VMS. Funny, things is I left those other systems and then was forced to come back to them, first RT11 and then NOS/KRONOS and then VMS and I remember grumbling. By then the ROMs had been forced in my muscle memory. '/' also has the advantage of being a non-shift ​Hmm, so was dot, which is what TSS and MTS used.​ DEC was using it as the <base>.<ext> separator, but I think Ken could have used it as easily at the time since the idea of <ext> and exposing semantics of what the file was in the name was foreign to UNIX (although was used in other systems as we know).