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- Subject: IBM SDLC and Token-Ring Conflict
- Date: March 28, 1988
- - - - - - - - - - - - - - - - - - - - - - - - - -
- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
- !!! NOTE: This problem has been fixed in later releases !!!
- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-
- PROBLEM: The problems we've heard of from a few customers using IBM
- SDLC cards in Token-Ring workstations seems to be tied to the
- fact that the SDLC card uses IRQ 3.
-
- SOLUTION: Although there seems to be no IBM documentation to verify
- this, when the TRN board is changed to either IRQ 2 or 7, we
- were able to run the IBM 3270 emulation program without any
- problem (with both the 1985 and the 1987 versions of
- TOKREUI.COM). Visual inspection of the SDLC board by ATS
- hardware experts verified that the board does use IRQ 3.
-
- There's more on this subject. What we sent before was
- somewhat of a half truth. Well, here's another quarter of
- it!
-
- There are actually two different IBM 3270 emulation boards:
-
- "3270 Coax attached board" - connects to a 3174
-
- "3270 SDLC remote" - connects to a SYNC modem
-
- These are probably not exact IBM product names. It will be
- important to differentiate with customers between these two
- cards for a couple of reasons. Sometimes people refer to the
- Coax board as an SDLC card as well. They operate
- differently; the SDLC board still appears to use IRQ 3, but
- it appears that the Coax board does not use any IRQ but,
- rather, dual-ported memory. (We're still verifying this.)
-
- Another item: CXI is now testing a 3rd board from IBM. It's
- a combination of the other two in a MCA version. It should
- be able to perform either SDLC or Coax communications.
-