| Short name | Description | Year | Manufacturer | Runnable | Parent |
|---|---|---|---|---|---|
| msx_slot_rs232 | MSX Internal RS-232C | No | |||
| msx_slot_rs232_mitsubishi | Mitsubishi Internal RS-232C | No | |||
| msx_slot_rs232_sony | Sony Internal RS-232C | No | |||
| msx_slot_rs232_svi738 | SVI-738 Internal RS-232C | No | |||
| msx_slot_rs232_toshiba | Toshiba Internal RS-232C | No | |||
| msx_slot_rs232_toshiba_hx3x | Toshiba HX-33/HX-34 Internal RS-232C and firmware | No |