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
4
com1,com2 com3
IRQ 3
The Mercantile System used American colonies to supply England's needs for resources.
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
It is known as a server.
capitolism
COM2 and COM4 use the same interrupt by default (IRQ3). The same is also true for COM1 and COM3 (IRQ4).
COM1 and COM3, IRQ4
The "com" ports are computer, serical communications ports (normally RS-232).
When the memory resources are scarce. We use compaction.