Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!bellcore!texbell!vector!telecom-gateway From: dik@cwi.nl (Dik T. Winter) Newsgroups: comp.dcom.telecom Subject: Re: The 'Public Telegraph Office' Message-ID:Date: 24 Sep 89 23:44:45 GMT Sender: news@vector.Dallas.TX.US Lines: 45 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 405, message 4 of 5 > [Moderator's Note: Well I believe it was the 'shift - 7' now that you mention > it; and of course control-G is Ascii 7. No, it was shift-J. > Weren't the 'number-shift' keys > essentially like control keys? How did they get line feed, carriage return, > ENQ (who are you?) and answerback without control codes? I have here CCITT #2 which says that LF and CR are valid both shifted and unshifted and ENQ=shift-D. This gives me some remembrances. The first computer I did use had Telex typewriters as consoles. However, they where very advanced. They had a four row keyboard and would remember whether the last shift was figures or letters. So when you entered a symbol not in the current shift the apparatus whould not generate it unless you entered the correct shift first. (Yes, it was made by Siemens.) Here follows the CCITT #2 code table: Letters Figures 0 8 16 24 0 8 16 24 0 space LF E A space LF 3 - 1 T L Z W 5 ) + 2 2 CR R D J CR 4 ENQ BEL 3 O G B figures 9 undef ? figures 4 nil I S U nil 8 ' 7 5 H P Y Q undef 0 6 1 6 N C F K , : undef ( 7 M V X letters . = / letters A question is: where in this whole lot of bits figures the sprocket hole; i.e. is it 1.2.4.o.8.16 or 16.8.4.o.2.1? Next to me lies a lot of 5-level paper taper, but I cannot yet figure it. This is CCITT #2 or Baudot. There is another 5-level code: CCITT #1 which has also another name. I must have the code somewhere, but am not inclined to dig it up unless requested. There appears also to be some different Telex codes in the US. If I remember right, a 3 out of 7 code or somesuch and a 8 level code (but not ASCII). I have the codings somewhere (in the same place as CCITT #1) but do not know under what circomstances they were used. Any help is appreciated. dik t. winter, cwi, amsterdam, nederland dik@cwi.nl