mcgurrin@MITRE.ARPA (12/19/87)
In browsing through the IIGS hardware and firmware technical manuals, I noticed that the serial port uses a multi-protocol chip that supports synchronous as well as asynchronous communications. Does anyone know if this means one could use the serial port as a synchronous port, assuming the appropriate driver software was written, or is there no way to access the necessary control lines, etc.? I assume that if possible it would require directly accessing the chip, not using firmware. I would be particularly curious if HDLC LAPB could be supported with the appropriate software (a IIGS with X.25? an interesting concept!).
gwyn@brl-smoke.ARPA (Doug Gwyn ) (12/20/87)
In article <8712181616.AA20668@mitre.arpa> mcgurrin@MITRE.ARPA writes: >In browsing through the IIGS hardware and firmware technical manuals, I noticed >that the serial port uses a multi-protocol chip that supports synchronous >as well as asynchronous communications. I seem to recall from looking through the schematics that the chip was hard-wired into the machine in a way that assumed it would be used in serial mode only. However, I might be mistaken. You can certainly directly access the chip registers to request HDLC etc. modes; several months ago I posted a C header file containing appropriate definitions. If you need a copy, send me mail with a return address that I can parse (none of this BITnet nonsense!) -- Gwyn@BRL.MIL
ranger@ecsvax.UUCP (Rick Fincher) (12/23/87)
In article <8712181616.AA20668@mitre.arpa>, mcgurrin@MITRE.ARPA writes: > In browsing through the IIGS hardware and firmware technical manuals, I noticed > that the serial port uses a multi-protocol chip that supports synchronous > as well as asynchronous communications. Does anyone know if this means one > could use the serial port as a synchronous port, assuming the appropriate > driver software was written, or is there no way to access the necessary > control lines, etc.? I assume that if possible it would require directly > accessing the chip, not using firmware. I would be particularly curious > if HDLC LAPB could be supported with the appropriate software (a IIGS with > X.25? an interesting concept!). The Zilog 8530 SCC chip is the same as that used in the Mac. The synchronous mode is used with Appletalk but no one has used it for IBM style synchronous communications. If it could be donm[De [D, someone would have done it on the Mac by now, Iwould think. You still need an IRMA board for the Mac or some other such device to do it. These are available for the Apple II, have been for years, but are very expensive. Rick