Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bbn!oberon!pollux.usc.edu!papa
From: papa@pollux.usc.edu (Marco Papa)
Newsgroups: comp.sys.amiga.tech
Subject: Re: DTR and serial.device
Message-ID: <15078@oberon.USC.EDU>
Date: 1 Feb 89 06:36:44 GMT
References: <15000@oberon.USC.EDU> <6992@killer.DALLAS.TX.US>
Sender: news@oberon.USC.EDU
Reply-To: papa@pollux.usc.edu (Marco Papa)
Distribution: usa
Organization: Felsina Software, Los Angeles, CA
Lines: 35

In article <6992@killer.DALLAS.TX.US> elg@killer.DALLAS.TX.US (Eric Green) writes:
|in article <15000@oberon.USC.EDU|, papa@pollux.usc.edu (Marco Papa) says:
|| In article <10511@well.UUCP| jimbo@well.UUCP (Jim Bolton) writes:
|||looking at the way I handle DTR.  Currently to drop DTR I close the serial
|||device, wait 1 second, and then reopen the serial device.
|| ....
|||So, I would like to know if it is possible to inhibit DTR on the Amiga's
                                                 ^^^^^^^^^^^^^^^^^^^^^^^^
|||RS-232 serial port and if so could you point me in the right direction.
   ^^^^^^^^^^^^^^^^^^
|| 
|| This is some code that might be helpful to you.
|[... some C code to hack directly at the CIA to turn off the DTR bit]
|
|Note that hacking straight at the CIA will *BREAK* if you are using a
|multiserial card and accessing any serial device other than unit 0.
 ^^^^^^^^^^^^^^^^
|Now that we are FINALLY getting multi-serial cards, PLEASE don't do
|something brain-damaged like this! 

Read the original question, dude. He said "Amiga RS-232 serial port",
NOT a multi-serial device.

|Your current scheme, closing the serial.device, probably will break
|the least when used in a multiserial environment.

As Bryce posted, closing/wait/opening the "current" (multi)serial
device is the only way to drop DTR in a compatible way, and all
multi-serial hardware manufacturers should support it.

-- Marco Papa 'Doc'
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