From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Edenyard" Subject: DOSemu serial port problem Date: Fri, 31 Oct 2003 09:36:39 Sender: linux-msdos-owner@vger.kernel.org Message-ID: <200310310937.AMB57095@msgdirector1.onetel.net.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-msdos@vger.kernel.org I'd very much appreciate help with this serial port problem: I've installed DOSemu V1.1.99 from source an an Athlon and have got it running quite well on Slackware 9.1 (2.4.22 kernel). It recognises the DOS partition on the HDD, boots from the IBM DOS there and will run programmes like Xtree and Wordstar without any problems. However, I have a programme written in Turbo Basic that accesses the DOS COM1 serial port hardware (UART registers, etc.) directly and I'm having trouble getting it to talk to the port properly under DOSemu. The port is a standard 16550A UART on the motherboard and works correctly under Linux. This is the error message I get as DOSemu is coming up: ERROR: PORT: conflicting devices: COM1 & std port io The programme appears to be able to send out of the port but cannot get any data coming back in. I've set /etc/dosemu/dosemu.conf to deal with the COM1 port like this: $_com1 = "/dev/ttyS0 irq 4" $_ports = " device /dev/ttyS0 fast range 0x3f8,0x3ff" $_irqpassing = "4" but I can't stop the 'conflict' message or get any data from the port into my programme. The remainder of the programme appears to work properly, even printing to what it thinks is LPT1. I'm running DOSemu as root (which I believe I have to do in order to gget access to the UART at /dev/ttyS0 - is this true?) and it's running in an Xterm window. I've an idea that I need to tell Linux to ignore COM1 (ttyS0) so that the DOS programme can have it, but I don't know whether this idea is sensible and, if so, how to do this. Is there a parameter to give to a module or the kernel at boot time, or something like that? I've tried DOSemu V1.0.2 and get the same problem, so I'm sure it's something I'm doing that's messing it up, rather than a DOSemu bug. Hope this isn't a dumb question I'm asking. Thanks for any help on this! Gerald.