Originally Posted by pandy71
There is no multiport MIDI per se as in ST or Amiga you have only one serial port - to do multiport you need some smart buffer and sufficiently faster main serial port co combine data from multi port solution - AFAIK there is no such HW for ST thus there is no real multiport MIDI on ST.
Of course smart buffering can be done on some uC with proper (embedded software) then you can have multi I/O MIDI but still this will be kind of hack - pure math nothing else.
I own one of the ST multiport adapters, the Unitor N. It plugs into ST's cartridge port which is much faster than an RS232 serial port. It brings the total number of MIDI ports to 6 on the ST. It also adds SMPTE so the sequencer can be synced to a tape recorder. Steinberg produced a similar device. There were many such devices for the Mac and I have an old one for the PC as well that uses the parallel port and adds two MIDI ports that can be used alongside the joystick midi port on the PC.