FILE: RS232.TXT

IBM-PC
======

RS-232 address table is found at offset 00H in the BIOS data area
BIOS serial-port service routines are accessed through interrupt 14H

COM1   3F8H  IRQ4
COM2   2F8H  IRQ3
COM3   3E8H  IRQ4
COM4   2E8H  IRQ3

IBM PC Serial Ports:
====================
PC, XT 25-pin serial port DB-25P connector configured as DTE (Data-
       Terminal-Equipment)  RS-232c standard:

  Pin  Description              Direction
   1   Chassis ground           -
   2   Transmit data       TX   Out
   3   Receive data        RX   In
   4   Request to send     RTS  Out
   5   Clear to send       CTS  In
   6   Data set ready      DSR  In
   7   Signal Ground       SG   -
   8   Data Carrier detect DCD  In
   9   [+Transmit Current loop]
  11   [-Transmit Current loop]
  18   [+Rec.Current loop 20ma]
  20   Data terminal ready DTR  Out
  22   Ring indicator      RI   In
  25   [-Rec.Current loop 20ma]

A modem or printer would have a DCE (Data-Communication-Equipment)
connector, with the functions of pins 2-3, 4-5, and 6-20 reversed;
and the directions of DCD and RI reversed as well.

AT 9-pin serial port connector (DB-9P) configured as DTE device:

  Pin  Description              Direction
   1   Data carrier detect DCD  In
   2   Receive data        RX   In
   3   Transmit data       TX   Out
   4   Data terminal ready DTR  Out
   5   Signal Ground       SG   -
   6   Data Set Ready      DSR  In
   7   Request to send     RTS  Out
   8   Clear to send       CTS  In
   9   Ring indicator      RI   In


DEC Serial Ports:
==================
25 Pin

Pin  Function                    Abr                         FDXA FDXB FDXC
-------------------------------------------------------------------------------
1    Protective Ground           PGND                         X    X    X
2    Transmit Data               TXD                          X    X    X
3    Receive Data                RXD                          X    X    X
4    Request to Send             RTS                          X    X    X
5    Clear to Send               CTS                          X    X    X
6    Data Set Ready              DSR                          X    X    X
7    Signal Ground               SGND                         X    X    X
8    Carrier Detect              CD                                X    X
9    Reserved
10   Reserved
11   Unassigned
12   Secondary Carrier Detect    SI                                X
     (Speed Indicator)
13   Secondary Clear to Send     SCTS                                   X
14   Secondary Transmit Data     STXD                                   X
15   Transmit Clock              TSET                                   X
16   Secondary Receive Data      SRXD
17   Receiver Clock              RSET                                   X
18   Unassigned
19   Secondary Request to Send   SRTS                                   X
20   Data Terminal Ready         DTR                          X    X    X
21   Signal Quality Detect
22   Ring Indicater              RI                           -    -    -
23   Data signal rate select     SPDS                              X
     (Speed Select)
24   Transmit clock
25   Unassigned
-------------------------------------------------------------------------------

            
Pin  Abr    RS232c IBMPC VT220 VT320   
-------------------------------------------------------------------------------
1    PGND     x      x
2    TXD      x      x     x     x
3    RXD      x      x     x     x
4    RTS      x      x     x     x
5    CTS      x      x     x     x
6    DSR      x      x     x     x
7    SGND     x      x     x     x
8    CD       x      x     x     x
9  +TXD Curlp x
10   
11 -TXD Curlp x
12   SI                    x     x
13   SCTS
14   STXD      
15   TSET      
16   SRXD
17   RSET      
18 +RXD.Crtlp x
19   SRTS      
20   DTR      x      x     x     x
21   
22   RI       x      x
23   SPDS                  x     x
24   
25 -RXD.Crtlp x
-------------------------------------------------------------------------------

9 Pin Printer Serial Port (VT220)

Pin  Function                    Abr  
--------------------------------------
1    Protective Ground           PGND
2    Transmit Data               TXD
3    Receive Data                RXD
4    Request to Send             RTS
5    Data Terminal Ready         DTS
6    Data Set Ready              DSR
7    Signal Ground               SGND
8
9
--------------------------------------


6 Pin Serial Port
+------------+
|1 2 3 4 5 6 |
+-------+  +-+
        +--+

Pin  Function                    Abr  
--------------------------------------
1    Data Terminal Ready         DTS
2    Transmit Data               TXD+
3    Transmit Signal Ground      TDX-
4    Receive  Signal Ground      RXD-
5    Receive Data                RXD+
6    Data Set Ready              DSR
--------------------------------------


20ma Port Interface Signals

Pin  Function
----------------
1    -12v
2    Transmit -
3    Receive -
5    Transmit +
7    Receive +
8    Ground
----------------

SERIAL CABLES
=============

FX DATA TRANSFER CABLES                    P1     For Toshiba T1000se
=======================                    ==========================
FEMALE CONNECTORS
9-PIN 25-PIN  25-PIN 9-PIN                 PC      TERMINAL CABLE
---------------------------                ----------------------
5       7   -    7     5    GND - GND      9 PIN         25 PIN
3       2   -    3     2    TRX - RCX      FEMALE         MALE
7       4   -    5     8    RTS - CTS      ------        ------
6       6   -   20     4    DSR - DTR        2 ----------- 3
2       3   -    2     3    RCX - TRX        3 ----------- 2
8       5   -    4     7    CTS - RTS        5 ----------- 7
4      20   -    6     6    DTR - DSR

P2     FOR CRACK MONITOR - AMSTRAD    P3     FOR CRACK MONITOR - TOSHIBA
==================================    ==================================

     DATATAKER        PC                      DATATAKER        PC
     ---------------------                    ---------------------
      9 PIN         25 PIN                     9 PIN         9 PIN
      MALE          FEMALE                     MALE          FEMALE
      ------        ------                     ------        ------
      1,2 ----------- 1,7                      1,2 ----------- 5
        3 ----------- 3                          3 ----------- 2
        4 ----------- 2                          4 ----------- 3
       5,7                                      5,7
                      4,5                                      7,8
                      6,8,20                                  1,4,6

G206U MAGNETOMETER CABLE => PC
==============================

18 PIN         9 PIN     25 PIN
CONNECTOR      RS232     RS232
-------------------------------
A
B
C
D                5        7
E
F
G                7+8      4+5
H
J
K
L
M
N
T                2        3
U                3        2
S
R

 TERM            PRINTER             COMS           PRN
VT220 9PIN to EPSON 6PIN DIN to PC100B 25PIN to PC100B 25PIN
 FEMALE           MALE             FEMALE          MALE
--------------------------------------------------------------------
     1     -       6         -        1      -      1
     2     -       3         -        2      -      3
     3     -       1         -        3      -      2
     4       
     5     -       2         -        5      -      4
     6     -       2         -        6      -     20
     7     -       5         -        7      -      7



               EPSON MALE PLUG

                   1.    5.
                      6.
                   2.    4.
                      3.





9 PIN FEMALE - 25 PIN MALE   SERIAL PLUG FOR HP PLOTTER TO PC
--------------------------------------------------------------
        1   ------ 4
        2   ------ 2
        3   ------ 3
        4   ------ 5,6
        5   ------ 7
        6,8 ------ 20
        7   ------ 8

