IBM Aptiva 2170 Hardware Maintenance Service Manual page 43

Item-
Serial port
Parallel port
Game port
USB
Machine Type 2170
Supports one high speed NS 16C550 compatible UARTs with
send/receive 16 bytes FIFOs
Machine Type 2171 and 2172
Support two high speed NS 16C550 compatible UARTs with
send/receive 16 bytes FIFOs
RS232D electrical interface compliant
Supports SPP (IBM PC/XT, PC/AT, PS/2) compatible, EPP
(IEEE 1284 compliance), ECP (IEEE 1284 compliance)
interface.
IEEE 1284 compliant
Game port interface for joystick. It also supports MIDI.
Supports Universal HCI Specification for USB 1.0
Interface
General Information 9