the first is directly wired to the DB9 connector on the slot cover of the card
the second is for the ribbon cable of the DB25 connector on the separate slot cover
the MC68681 is a 4 MHz version overclocked to 7 MHz in order to reach the 115200 bps transfer rate
the 31250 bps MIDI rate is supported only when the 7.3728 MHz oscillator is replaced by 4 MHz - this disables the higher bitrates (115200, 57600, 33600, 19200)
does not support the RI (Ring) signal
supported by Linux and NetBSD
parallel interface
one bidirectional DB25 parallel port controlled by MC6821P