import io

const portCOM1 = 0x3f8'u16

proc init*() =
   io.outb((portCOM1 + 1, 0x00'u8));    # Disable all interrupts
   io.outb((portCOM1 + 3, 0x80'u8));    # Enable DLAB (set baud rate divisor)
   io.outb((portCOM1 + 0, 0x03'u8));    # Set divisor to 3 (lo byte) 38400 baud
   io.outb((portCOM1 + 1, 0x00'u8));    #                  (hi byte)
   io.outb((portCOM1 + 3, 0x03'u8));    # 8 bits, no parity, one stop bit
   io.outb((portCOM1 + 2, 0xC7'u8));    # Enable FIFO, clear them, with 14-byte threshold
   io.outb((portCOM1 + 4, 0x0B'u8));    # IRQs enabled, RTS/DSR set

proc isTransitEmpty(): uint =
  result = io.inb(portCOM1 + 5) and 0x20'u

proc write*(input: char) =
  while isTransitEmpty() == 0:
    discard
  io.outb((portCOM1, uint8(input)))

proc write*(input: string) =
  for i in 0 .. input.len - 1:
    write(input[i])
  write('\L')