Kirk, I learned my communications in the wonderful days of the start-stop 1050 and its typewriter - golfball - sisters and brothers (late '60s)
Here, although the line feed was fast, it was necessary to add null characters after the carriage return in order to allow for actual carriage movement. I believe the algorithm was to round the line position at the end of the line to the next unit of 10 and then divide by 10. This null padding also applied to use of the tab key. Then, of course, the program had to know how the tabs were set. I seem to remember even having to concern myself with this issue with the 3102 ASCII printer - anyone remember that? Although it was buffered it could be overrun. (early '80s) Chris Mason ----- Original Message ----- From: "Kirk Talman" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <IBM-MAIN@BAMA.UA.EDU> Sent: Thursday, 29 June, 2006 7:59 PM Subject: Re: Character set conversoin headaches > The CRLF existed in the early 60's. When you drive a Teletype (a > mechanical printer, which when excited sounds like a washing machine > mating with a jackhammer) you need to account for the slowness of the > carriage. You did the carriage return before the line feed to allow time > for the return of the print mechanism to the left side before the carriage > roller advanced and printing resumed. > > I remember when our lab at Oak Ridge got a PDP8S to control a magnetic > electron spectrometer. We were outputting from a multichannel analyzer > using BPRE paper tape punch that was loud. But that could not compare to > the 8S just printing messages. > > The good old days? -- sort of. > > You can't see the lab at the Graphite Reactor National Site any more > because they put a security portal half way down the valley from the > townsite to X-10. > > IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> wrote on 06/29/2006 > 01:28:59 PM: > > >> -----Original Message----- > >> From: IBM Mainframe Discussion List > >> [mailto:[EMAIL PROTECTED] On Behalf Of Shmuel Metz (Seymour J.) > >> Sent: Thursday, June 29, 2006 8:38 AM > >> To: IBM-MAIN@BAMA.UA.EDU > >> Subject: Re: Character set conversoin headaches > > > <snip> > > >> The obvious reason is that NL is new line; that's what it has been > >> there for since the advent of the S/360. What is bizarre was the Unix > >> decision to use LF as an NL sequence instead of the traditional CRLF. > > > Question: You state that CRLF is "traditional". I was under the > > impression that CRLF originated with CP/M-80 from Digital Research. The > > LF is from UNIX. I think that the original UNIX predates CP/M-80. Yes, I > > had a CP/M-80 system many years ago. > > > From what I understand, CP/M-80 used CRLF because the printers that that > > were driven from the microprocessor based systems of the time did not > > implement a "new line" character at all. So, to simplify things, text > > files were delimited with CRLF on disk so that the "pip" (Peripherial > > Interchange Program ) program could be used to print a text file simply > > by "copying" it to "lpt:" (IIRC that was the "name" of the printer). > > > I hadn't noticed that there is not a NL in ASCII. Good catch! > > > <snip> > > >> -- > >> Shmuel (Seymour J.) Metz, SysProg and JOAT > > > -- > > John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
