COM.SYS

This driver loads the serial port support to be used by an external device like a modem. There is also available COM02.SYS which is available for the Micro Channel architecture.

CONFIG.SYS
This driver is required for serial communications. DEVICE=C:\OS2\Boot\COM.SYS

TIP: below. This line MUST appear after any driver that uses a communications port. Older versions of COM.SYS are limited to 57600 Baud, newer ones (e.g. delivered with Warp 4) are able to do 115200 Baud. Beginning with build 10.042 PCI Add-On cards with implemented software interrupt sharing are supported too, beginning with build 10.052 there are 16 com ports available and beginning with build 10.068 Combo Cards are supported.

TIP: There are two very good replacement drivers called SIO.SYS\VSIO.SYS.

TIP: To add support for COM3 and COM4 at location 3E8 with IRQ 4 and 2E8 with IRQ 3 respectively, add (3,3E8,4) (4,2E8,3) to the DEVICE line, e.g. DEVICE=drive:\OS2\COM.SYS (3,3E8,4) (4,2E8,3) You can also use this method to change a COM ports assigned IRQ. The normal address for COM1 is 3F8 and IRQ 4, for COM2 2F8 and IRQ3.

TIP: With ThinkPads should the address be added. e.g: DEVICE=drive:\OS2\BOOT\COM.SYS (1,3F8,4) (2,2F8,3)

Parameter:


 * /V - Verbose (since 10.052)
 * /W - Wait verbose mode (since 10.052). Displaying pauses with a "Press Enter to continue..." message.
 * /F - Find COM ports on PCI combo (serial/parallel) cards automatically (since 10.068).