Paolo Bonzini <pbonz...@redhat.com> writes:
> On 04/04/19 22:49, Philippe Mathieu-Daudé wrote:
>> While I wonder if someone still use the r4k machine, I have more doubts
>> about users running with more the 2 -serial options...
>
> I sort of remember ISA extension cards that had jumpers or dip switches
> to choose between COM1/COM2/COM3/COM4...
They still exist, with I/O ports and IRQ lines selectable via jumpers &
DIP switches. Traditionally:
COM1: I/O port 0x3F8, IRQ 4
COM2: I/O port 0x2F8, IRQ 3
COM3: I/O port 0x3E8, IRQ 4
COM4: I/O port 0x2E8, IRQ 3
