Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!usc!ucsd!ucbvax!CUNYVM.CUNY.EDU!PIRARD%vm1.ulg.ac.be From: PIRARD%vm1.ulg.ac.be@CUNYVM.CUNY.EDU (Andr'e PIRARD) Newsgroups: comp.protocols.tcp-ip Subject: needs VT220 host, was emulation Message-ID: <9012122001.AA04654@ucbvax.Berkeley.EDU> Date: 11 Dec 90 08:38:52 GMT References: Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 62 On Wed, 19 Sep 90 11:29:05 -0500 James B. Van Bokkelen said: >If it has to replace ours, he needs an IBM PC DOS VT220 emulator with >7-bit and 8-bit support, the ISO Latin character set, keyboard and >display re-mapping and print screen support, built into a Telnet with >a built-in FTP server and multi-session capability. Novell (Excelan) >offers VT220 in their product for the EXOS205, but I don't know its >capabilities. Sun, IBM and 3Com had VT100 last I knew, I don't know >what Beame & Whiteside offers. One could also get a VT220 emulator >from one of the Ascii emulator specialists and use it with an INT 14 >Telnet redirector. I don't recall any INT 14 redirector or VT220 >emulator Telnets that are free... Fine to us, those "foreign" language speakers, James. Now we have the terminal, how can we have the host. Let me explain. To us, computers codes are just as different as EBCDIC is from ASCII. This is because we do have to use an 8-bit code and the "ASCII extension" of the PC and the Macintosh, for example, are not compatible. It needs little reasoning to come to the conclusion that a standard code has to be defined to be used on the communication line, just as ASCII is, that is of course an extension of ASCII. Telnet binary mode, for one, is not enough because it does not enforce computers to use the same exchange code. The same problem occurs for several other application protocols and the rule should be that either a system simply uses that standard code or has to translate its own to standard when exchanging data on communication lines. A 8-bit invertible translation has to be defined for each proprietary code, even if the character set does not match the standard set exactly. The programming key is to use the standard code in memory and provide a translation at the device level (keyboard, screen, file), optional by possibly being null. It needs very little indeed to fit the 4th wheel to the great TCP/IP car. Unhappily, most of the TCP/IP protocols do not define that 8-bit code (X is the counter example, however) worse have a tendency to restrict to 7-bit. Everyone, including X, seems to agree that this code is ISO 8859/1 (for Latin group 1 languages, others would use other versions untranslatable to each other, except for the common ASCII lower half). But I find this agreement too silent. Which 8-bit code to use seems to be left to anybody's whim. Unix moves to 8-bit, but which mainly depends on the character code of the devices (terminals and printers mainly). I have heard of installations using Unix with PC code page 850 (exactly the same character set as ISO 8859/1, but with different code points), even IBM saying that it's the code of AIX. Thus, VT220 and Macintoshes cannot be used. I've heard that SunOS 4.1 starts using ISO 8859/1 (is that correct?). The higher VT models emulation does just that: translate ISO 8859 to local. The specific question is: how does this integrate with Telnet and how does a Unix host have to be setup to use 8859? Should a 7-bit path be used with SO/SI shifting for both screen and keyboard (seems a pain, especially to recover from entering the wrong mode), or will the emulator request binary mode and Unix understand? Unix applications (of those being able to process 8 bits) should work unaware of terminal setup requirements. How will the VT terminal enter ISO 8859/1 mode (or shouldn't the emulator best be locally configurable to use ISO 8859/1 without any system or application action?). In a word, how use ISO 8859/1 as simply as ASCII? Sorry I am not a Unix man. Please excuse my difficulties to use this standard language on communication lines, and believe I'd really like to be able to use my own to send correct mail to French talking people, including those in so far away Quebec :-) Andr'e PIRARD SEGI, Univ. de Li`ege B26 - Sart Tilman B-4000 Li`ege 1 (Belgium) pirard@vm1.ulg.ac.be or PIRARD%BLIULG11.BITNET@CUNYVM.CUNY.EDU