ifam655@ccwf.cc.utexas.edu (Jeff Lessem) (04/20/91)
How can I set up more than 2 serial ports on my AT running OS/2 1.21? It is a Dell 210 and I am using the Dell OEM version of OS/2 1.21. I have 2 built in serial ports, and an internal modem. The modem changes my second built in serial port to com3 or com4, depending how I configure it. Is there any way to change the com device driver to get access to this port?
d9mikael@dtek.chalmers.se (Mikael Wahlgren) (04/21/91)
In article <47518@ut-emx.uucp> ifam655@ccwf.cc.utexas.edu (Jeff Lessem) writes: >How can I set up more than 2 serial ports on my AT running OS/2 1.21? This is one of the most commonly asked questions. There is a public domain COM0x-replacement, that lets you specify both IRQ-level and I/O-address. It is possible to install this driver multiple times with different values, making it possible to use any amount of serial ports, as long as you install the ports at different I/O-addresses (of course) AND DIFFERENT IRQ's, as the driver don't handle shared interrupts. The driver is also said to be more reliable than the included COM0x-driver. It is bundled with one driver for the 16450 UART and another for the 16550 UART. If you have a 8250 UART, you are out of luck, but may still get what you want if you install the included COM0x-driver for two ports, and the PD driver for the third port (which MUST have a 16450 or 16550 UART). The driver is called COM16550.Z(IP, and is available at some BBS's around the world. Mail me a message if you are interested and I can mail you the package, or I could send it to the os2 binaries. Mikael Wahlgren Mikael Wahlgren d9mikael@dtek.chalmers.se
gah@hood.hood.caltech.edu (Glen Herrmannsfeldt) (04/23/91)
I got COM3/4 by patching COM01.SYS, and loading the original and patched copy. As said before, you MUST have a different IRQ for each port. Note that IRQ2 is interrupt level 9 in the OS/2 numbering system. This is the way the 8259 is wired up in AT type machines. By the waay, why won't 8250's work with OS/2? Is it just speed, or is it more complicated than that.
d9mikael@dtek.chalmers.se (Mikael Wahlgren) (04/24/91)
In article <gah.672403820@hood> gah@hood.hood.caltech.edu (Glen Herrmannsfeldt) writes: >By the waay, why won't 8250's work with OS/2? Is it just speed, >or is it more complicated than that. There is no general rule why the 8250 won't work on an OS/2 system. If you use the standard COM0x.SYS driver, the 8250 in fact very often WILL work. The COM16550-drivers I mentioned before, are special designed for the 16450/16550 UARTs though. But even if you use the standard COM0x.SYS driver, you MAY get problems if you have the 8250 UART. Sometimes it will malfunction, and sometimes the driver will refuse to install at all. There area lot of different versions of the 8250 UART available, and some of them are buggy (don't work with some special data formats, and some won't work with send data IRQ). Mikael Wahlgren d9mikael@dtek.chalmers.se