COM1 and COM2 originally referred to the serial port interfaces on a PC. Now they can refer to any port, virtual or physical.
com1,com2 com3
well COM1, COM2, COM3, and COM4 are sometimes configured as Serial Ports.
COM1-IRQ 4, memory addresses 03F8-03FF COM2-IRQ 3, memory addresses 02F8-02FF COM3-IRQ 4, memory addresses 03E8-03EF COM4-IRQ 3, memory addresses 02E8-02EF pg. 396
The "com" ports are computer, serical communications ports (normally RS-232).
COM2 and COM4 use the same interrupt by default (IRQ3). The same is also true for COM1 and COM3 (IRQ4).
COM1 is assigned 3F8h and uses IRQ Channel 4, COM2 is assigned 2F8h and uses IRQ Channel 3, COM3 is assigned 3E8h and uses IRQ Channel 4
CON, PRN, AUX, CLOCK$, NUL COM0, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9 LPT0, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.
COM1 and COM3, IRQ4
The serial ports are named ttyS0, ttyS1, etc.And usually correspond respectively to COM1, COM2, etc. in DOS/Windows
Yes on a modern computer you will need a USB to 9 pin RS232 converter or previously use the LPT parallel port.
Hi, correct combination of default combination of COM ports and IRQ is given below: 1. com1 and com3 - IRQ4 2. com2 and com4 - IRQ3 below link can easily explain the answer in details. You can even see this in device manager properties. i.e. mycomputer > properties > device manager> IDE/ATA controller > resources > irq=20 link : http://www.webopedia.com/quick_ref/IRQnumbers.asp
There's no limit to the number of serial ports. The maximum number for the traditional ports is 2 (COM1/COM3 and COM2/COM4). Plus you can attach additional serial port adapters to a USB port, up to 127 per controller.