IBM 5150 - Page 253

The following is an illustration of data terminal equipment
connected
to an external modem using connections defined by the
RS-232C interface standard:
Data
Terminal
Equipment
Communications
Line
---:;;::''''''==--------
/ "
// /"/ .......... ' ......
// Adapter /// Cable Conforming '" "
/
/// To RS-232C Standards "
/,. ........................... , "'"
/ , ,
/ /EIA/CCITT Telephone Co. "
Line
Number Lead Number
Protective Ground 0-AA/101
Signal Ground @-AB/102
Transmitted Data @--BA/103
Received Data ®--BB/104
Request to Send 0- CAl 105
Clear to Send ®- CB/1 06
Data Set Ready @-CC/107
Data
Terminal
Data Terminal Ready &-CD/10B.2
Modem
Equip-
Connect Data Set to Line ------&- .. 11 OB.1
ment
Received Line Signal Detector 8 CF 1109
Speed Select
Transmit Signal Element Timing ~ DB/114
Receive Signal Element Timing ~ 00/115
Select Standby @- 1116 H
Ring Indicator @- DE/125
Test ~**/H'
I
External Modem Cable Connector
131211109 8 7 6 5 4 3 2 1
rOO 0 0 0 0 0 0 0 0 0 o. °I
\,ooooooooooooj
2524 232221 20 1918 171615 14
. +(MOdemIDCE
L ___ .Data Terminal .___ Data Communications----l
I EqUIpment Equipment 'I
Pin Number
* Not used when business machine clocking is used_
* * Not standardized by EIA (Electronic Industries Association)_
* * * Not standardized by CCITT
8-4 Communications