
FROM: Daniel Lescohier

SUBJECT: IBM PCjr Adapter Cable for Serial Devices
         Pin out arrangement

I'll give you the pin connections (out of the IBM PCjr Technical Reference 
Manual) but you can also buy the cable from:

Paul Rau Consulting
260 N. Lincoln Way
Galt, CA 95632
(209) 745-9284 voice 9am-4pm PST, data 5pm-8am PST

My latest price list (from quite a few months ago) puts the price at 
$19 + $4 shipping.
 
Okay, here are the tech specs:

You need a nine-conductor cable, a "D"-shell connector, and a Berg-type 
connector.  Looking toward the head of the berg connector, with the 
wire trailing behind it, it is numbered:

A8 A7 A6 A5 A4 A3 A2 A1 \ Berg type connector
B8 B7 B6 B5 B4 B3 B2 B1 /
 
The connections:

System Connector   Cable                  25-pin D-Shell Connector
----------------   --------------------   ------------------------
A1                 Not Used
A2                 DATA TERMINAL READY    20
A3                 REQUEST TO SEND         4
A4                 TRANSMIT DATA           2
A5                 CARRIER DETECT          8
A6                 DATA SET READY          6
A7                 CLEAR TO SEND           5
A8                 RECEIVE DATA            3
B1                 SHIELD GND              1
B2                 SIGNAL GND              7
B3 - B8            Not Used
 

