wa371@sdcc12.UUCP (wa371) (05/22/85)
Question posed to the net: How can I interface IBM bisync with UNIX having RS-232 ports? Replies: :::::::::::::::::: From: Cliff Bamford <sdcrdcf!randvax!bamford@sdcsvax.sdcc12> Your question needs more careful formulation. The following may help. EIA RS232C and several roughly equivalent standards (RS422, CCITT V.29, X.21bis, etc) specify electrical properties, pin assignments, and pin-level signalling sequences between either: a modem and a terminal (rare in traditional IBM environments) or a modem and a cluster controller (much more common - eg, 3274s) or a modem and a front end (the host side of a link -- usually a 37x5) SDLC is a standard that specifies message formats and message exchange sequences. The messages flow in and out OVER the RS232 connection, but RS232 doesn't care what the messages contain -- only the SDLC partner at the other end of the link cares -- and his only interest is to insure checksums match, acknowledgements arrive, etc. Above both of these is SNA, which is a standard that defines the CONTENTS of the messages, and message content exchange sequences. Most non-World-Trade IBM SNA/SDLC systems already employ RS232C (although they use a strange version of a bus/tag connector instead of DB25 at the 37x5 side). Now, what's your question? Cliff Bamford, Data communications consultant (408) 662 0176 ARPA: bamford@Rand-Unix UUCP: {decvax, sdcrdcf, vortex}! randvax!bamford :::::::::::::::::::::: From: dcdwest!ittvax!decvax!genrad!mit-eddie!cybvax0!fbp@sdcsvax.sdcc12 (Rick Peralta) In article <279@sdcc12.UUCP> you write: >Does anyone know how to interface IBM 5251 terminal protocol, "SDLC" >synchronous, with RS232? Look at a Black Box catalog for a protocol converter. It is the easiest. The cost is about $2-4K. Rick ...!cybvax0!fbp ::::::::::::::::::::: end of replies. PS: Black Box does indeed offer as protocol converter that seems to fit. It is their model PQ-4(B). It has twinax inputs and an RS-232 output. It supposed to work with system 34, 36, 38 computers and emulate 5251 terminals. It is available as either bi-directional or receive-only. Either version is listed in their catalog for $1645.- I have not tried it, and the person who answered their technical support line, (412)746-5565, apparently had never heard of UNIX. Caveat emptor. Bernd <bear-nd> (Not affiliated with, nor speaking for U.C. San Diego) UUCP: ...!ucbvax!sdcsvax!sdcc12!wa371, ARPA: sdcsvax!sdcc12!wa371@nosc *** hooray for USENET ***