slayne@redstone-emh2.army.mil ( ASQNC-MIC-IT-TI/Sid Layne) (03/22/91)
Does anyone know of a software package (public or otherwise) for UNIX platforms, that will allow an IBM MVS 3278 terminal user the ability to emulate a vt100/220 terminal after telneting via TCP/IP from MVS to a UNIX platform. I am speaking of the exact oposite of software such as TN3270 that allows terminals in the UNIX world to emulate 3278 devices. Your responses will be greatly appreciated and can be sent to: slayne at REDSTONE-EMH2.ARMY.MIL (26.25.0.41)
rickert@mp.cs.niu.edu (Neil Rickert) (03/22/91)
In article <26320@adm.brl.mil> slayne@redstone-emh2.army.mil ( ASQNC-MIC-IT-TI/Sid Layne) writes: >Does anyone know of a software package (public or otherwise) for UNIX platforms, >that will allow an IBM MVS 3278 terminal user the ability to emulate a vt100/220 >terminal after telneting via TCP/IP from MVS to a UNIX platform. I am speaking >of the exact oposite of software such as TN3270 that allows terminals in the >UNIX world to emulate 3278 devices. Your responses will be greatly appreciated >and can be sent to: This probably can't be done. The vt100 terminal is unbuffered. Each keystroke is transmitted immediately. The 3278 is buffered. Up to a complete screenful of data is buffered on the terminal/control unit. The host doesn't even see a keystroke until the ENTER key or one of the PF keys or PA keys is used. At that time the complete screenful may be transmitted in a block operation. You can use software emulation, as in 'tn3270', to emulate a buffered terminal with an unbuffered one. All the emulation software must do is provide the buffering and screen management. Going the other way is a little more difficult, unless you have extra sensory perception built into your CPU. -- =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= Neil W. Rickert, Computer Science <rickert@cs.niu.edu> Northern Illinois Univ. DeKalb, IL 60115 +1-815-753-6940
phil@ux1.cso.uiuc.edu (Phil Howard KA9WGN) (03/24/91)
rickert@mp.cs.niu.edu (Neil Rickert) writes: > This probably can't be done. The vt100 terminal is unbuffered. Each >keystroke is transmitted immediately. The 3278 is buffered. Up to a complete >screenful of data is buffered on the terminal/control unit. The host doesn't >even see a keystroke until the ENTER key or one of the PF keys or PA keys is >used. At that time the complete screenful may be transmitted in a block >operation. > You can use software emulation, as in 'tn3270', to emulate a buffered terminal >with an unbuffered one. All the emulation software must do is provide the >buffering and screen management. Going the other way is a little more >difficult, unless you have extra sensory perception built into your CPU. Neil is right on the mark, except that I'd have used "definitely" in place of "probably". There are terminals on the market that can simultaneously behave like an IBM 3278 over a 93 ohm coax port and like a VT??? over an RS-232 port. There might well be derivatives of these that work on networks and do TN3270 emulations. PC and MAC programs also exist (NCSA/Clarkson TELNET). But if you are trying to retrofit existing hardware base of IBM 3270 class terminals, your time is better spent getting funding for new hardware. -- /***************************************************************************\ < Phil Howard -- KA9WGN -- phil@ux1.cso.uiuc.edu > \***************************************************************************/
MURRELL%UNCVX1.BITNET@ncsuvm.ncsu.edu (Jim Murrell) (03/29/91)
Don't know of such a piece of software, but it seems that it would be more likely to run under MVS than on the UNIX side. You may want to inquire thru some of the mainframe newsgroups. Having just installed their first version of TCP/IP on MVS, I suspect that the MVS people here at my site will be looking for the same fairly shortly. murrell@uncvx1.acs.unc.edu