Pinout of the 40-pin Berg connector used on the DL-11 (etc.).
KL8E is very similar (not sure about external clock).

Numbers in parentheses are EIA pin numbers connected in the BC05C modem cable
which aren't connected to anything on the DL-11.

ground		A	B	ground
force busy	C	D	(13)
TTL interlock	E	F	EIA TxD
20mA interlock	H	J	EIA RxD
20mA RxD +	K	L	(24)
EIA interlock	M	N	(15)
(19)		P	R	(17)
20mA RxD -	S	T	EIA CTS
(18)		U	V	EIA RTS
(10)		W	X	EIA RI
(9)		Y	Z	(6 - EIA DSR)
20mA TxD +	AA	BB	EIA CD
ext clk (TTL)	CC	DD	EIA DTR
20mA RDR -	EE	FF	EIA sec TxD
ext clk ena. L	HH	JJ	EIA sec RxD
20mA TxD -	KK	LL	(14)
(21)		MM	NN	(16)
20mA RDR +	PP	RR	(23)
TTL TxD		SS	TT	+5 VDC
ground		UU	VV	ground

Ext. clk. is a TTL signal which is sixteen times the baud rate selected by
position 9 on the baud rate selector switches (the position immediately
counterclockwise of 6 o'clock).  Ext clk ena L, when grounded, forces the
receiver to use the external clock regardless of how its rotary switch is set.

John Wilson, 12-Nov-1990