Serial Port
Most older ThinkPads have a Male DB-9 RS232 Serial Port, capable of running up to 115,200bps
Current ThinkPads no longer have a physical serial port, but still have the logic integrated, all that is required is to attach the ThinkPad to a supported Dock or Port Replicator with a serial port.
ThinkPads produced from 1994 onwards have a NS16550A compatible uart.
Models featuring this Technology
Legacy UART
- ThinkPad 220
 - ThinkPad 300
 - ThinkPad 350, 350C
 - ThinkPad 355, 355C, 355CS
 - ThinkPad 360, 360CS, 360C, 360P, 360PE
 - ThinkPad 500 (via port extension cable)
 - ThinkPad 510CS
 - ThinkPad 550BJ
 - ThinkPad 700, 700C
 - ThinkPad 710T
 - ThinkPad 720, 720C
 - ThinkPad 750, 750CS, 750C, 750P
 
16550A compatible UART
- ThinkPad 240, 240X
 - ThinkPad 310, 310D, 310E, 310ED
 - ThinkPad Template:345
 - ThinkPad 365CS, 365C, 365CSD, 365CD, 365E, 365ED, 365X, 365XD
 - ThinkPad 380, 380D, 380E, 380ED, 380XD, 380Z
 - ThinkPad 385D, 385ED, 385XD
 - ThinkPad 390, 390E, 390X
 - ThinkPad 560, 560E, 560X, 560Z
 - ThinkPad 570, 570E
 - ThinkPad 600, 600E, 600X
 - ThinkPad 701C, 701CS
 - ThinkPad 755C, 755CS, 755CSE, 755CE, 755CX, 755CV, 755CD, 755CDV
 - ThinkPad 760C, 760CD, 760EL, 760ELD, 760E, 760ED, 760L, 760LD, 760XL, 760XD
 - ThinkPad 765L, 765D
 - ThinkPad 770, 770E, 770ED, 770X, 770Z
 - ThinkPad 820, 850, 860
 - ThinkPad A20m, A20p, A21e, A21m, A21p, A22e, A22m, A22p, A30, A30p, A31, A31p, A275, A285, A475, A485
 - ThinkPad T20, T21, T22, T23, T30
 
16550B compatible UART
Categories: 
- 220
 - 300
 - 350
 - 350C
 - 355
 - 355C
 - 355CS
 - 360
 - 360CS
 - 360C
 - 360P
 - 360PE
 - 500
 - 510CS
 - 550BJ
 - 700
 - 700C
 - 710T
 - 720
 - 720C
 - 750
 - 750CS
 - 750C
 - 750P
 - 240
 - 240X
 - 310
 - 310D
 - 310E
 - 310ED
 - 365CS
 - 365C
 - 365CSD
 - 365CD
 - 365E
 - 365ED
 - 365X
 - 365XD
 - 380
 - 380D
 - 380E
 - 380ED
 - 380XD
 - 380Z
 - 385D
 - 385ED
 - 385XD
 - 390
 - 390E
 - 390X
 - 560
 - 560E
 - 560X
 - 560Z
 - 570
 - 570E
 - 600
 - 600E
 - 600X
 - 701C
 - 701CS
 - 755C
 - 755CS
 - 755CSE
 - 755CE
 - 755CX
 - 755CV
 - 755CD
 - 755CDV
 - 760C
 - 760CD
 - 760EL
 - 760ELD
 - 760E
 - 760ED
 - 760L
 - 760LD
 - 760XL
 - 760XD
 - 765L
 - 765D
 - 770
 - 770E
 - 770ED
 - 770X
 - 770Z
 - 820
 - 850
 - 860
 - A20m
 - A20p
 - A21e
 - A21m
 - A21p
 - A22e
 - A22m
 - A22p
 - A30
 - A30p
 - A31
 - A31p
 - A275
 - A285
 - A475
 - A485
 - T20
 - T21
 - T22
 - T23
 - T30
 - 360CSE
 - 360CE
 - 370C