From: "Tonu Aas" Newsgroups: comp.os.msdos.djgpp References: <03a701c2ccf6$5ccd6160$0600000a AT broadpark DOT no> Subject: Re: Determining interrupt vector for serial port Date: Wed, 5 Feb 2003 11:49:17 +0200 Lines: 21 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 NNTP-Posting-Host: ids.ids.ee Message-ID: <3e40df1b$1@news.infonet.ee> X-Trace: news.infonet.ee 1044438811 ids.ids.ee (5 Feb 2003 11:53:31 +0200) Organization: INFONET.EE To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com > > But I've been unable to discover how to "read" the associated IRQ > > value for each port. So far I've found them hardcoded as 4, 3, > 1. mask off all interrupts in the PIC (to prevent false positives) > 2. clear the in-service bits > 3. issue an UART command that raises it's IRQ line (e.g. an internal > loopback test) > 4. poll all in-service bits in the PIC > 5. and finally restore the PIC mask. Does this work in Windows DOS session also ? Maybe its not - PIC and UARTS are virtual. I think that only working and most portable way is to use some configuration in whatever form. Tõnu.