UNIBUS H854 header pinout

DEC produced several boards (the M9014, an extended height dual card, and the M9042 short dual card) cards to replace the standard BC11A UNIBUS cable. They plug into the same 'UNIBUS In' and 'UNIBUS Out' backplane slots as the BC11A, and contain three 2x20 headers for 40-conductor flat cables (known as H854 cables in DEC parlance); a pair of these cards, and three cables, perform the same role as a BC11A cable.

Both of these cards use the header pinout given below, so they may be used interchangeably. Following standard electrical engineering practise, every alternate wire in the flat cable is a ground: the active pins are B, D, F, J, L, N, R, T, V, X, Z, BB, DD, FF, JJ, LL, NN, RR, TT, VV (using the Berg header pin nomenclature).

By class

Signal	Assertion	Termination	BC11A pin	Berg header pin
Initialization and Shutdown
DC LO	L	Slow	BF2	J3-VV
AC LO	L	Slow	BF1	J2-VV
INIT	L	Fast	AA1	J3-Z
Arbitration
NPR	L	Fast	AS2	J3-B
BR7	L	Fast	AT2	J3-F
BR6	L	Fast	AU2	J3-L
BR5	L	Fast	BC1	J3-R
BR4	L	Fast	BD2	J3-V
NPG	H	Grant	AU1	J3-D
BG7	H	Grant	AV1	J3-J
BG6	H	Grant	BA1	J3-N
BG5	H	Grant	BB1	J3-T
BG4	H	Grant	BE2	J3-X
SACK	L	Fast	AR2	J3-TT
Address
A00	L	Fast	BH2	J1-D
A01	L	Fast	BH1	J1-B
A02	L	Fast	BJ2	J1-J
A03	L	Fast	BJ1	J1-F
A04	L	Fast	BK2	J1-N
A05	L	Fast	BK1	J1-L
A06	L	Fast	BL2	J1-T
A07	L	Fast	BL1	J1-R
A08	L	Fast	BM2	J1-X
A09	L	Fast	BM1	J1-V
A10	L	Fast	BN2	J1-BB
A11	L	Fast	BN1	J1-Z
A12	L	Fast	BP2	J1-FF
A13	L	Fast	BP1	J1-DD
A14	L	Fast	BR2	J1-LL
A15	L	Fast	BR1	J1-JJ
A16	L	Fast	BS2	J1-RR
A17	L	Fast	BS1	J1-NN
Data
D00	L	Fast	AC1	J2-B
D01	L	Fast	AD2	J2-F
D02	L	Fast	AD1	J2-D
D03	L	Fast	AE2	J2-L
D04	L	Fast	AE1	J2-J
D05	L	Fast	AF2	J2-R
D06	L	Fast	AF1	J2-N
D07	L	Fast	AH2	J2-Z
D08	L	Fast	AH1	J2-T
D09	L	Fast	AJ2	J2-Z
D10	L	Fast	AJ1	J2-X
D11	L	Fast	AK2	J2-DD
D12	L	Fast	AK1	J2-BB
D13	L	Fast	AL2	J2-JJ
D14	L	Fast	AL1	J2-FF
D15	L	Fast	AM2	J2-NN
Control
C0	L	Fast	BU2	J3-NN
C1	L	Fast	BT2	J1-TT
PA	L	Fast	AM1	J2-LL
PB	L	Fast	AN2	J2-RR
BBSY	L	Fast	AP2	J3-BB
MSYN	L	Fast	BV1	J3-LL
INTR	L	Fast	AB1	J3-FF
SSYN	L	Fast	BU1	J3-JJ
Power
Ground	N/A	N/A	AB2
Ground	N/A	N/A	AC2
Ground	N/A	N/A	AN1
Ground	N/A	N/A	AP1
Ground	N/A	N/A	AR1
Ground	N/A	N/A	AS1
Ground	N/A	N/A	AT1
Ground	N/A	N/A	AV2
Ground	N/A	N/A	BB2
Ground	N/A	N/A	BC2
Ground	N/A	N/A	BD1
Ground	N/A	N/A	BE1
Ground	N/A	N/A	BT1
Ground	N/A	N/A	BV2
Ground	N/A	N/A	N/A	J1-VV
Ground	N/A	N/A	N/A	J2-TT
Ground	N/A	N/A	N/A	J3-DD
Ground	N/A	N/A	N/A	J3-RR
+5	N/A	N/A	AA2
+5	N/A	N/A	BA2
Other
No connection	N/A	N/A	BA2
No connection	N/A	N/A	BB2

By Berg pin

Signal	Assertion	Termination	BC11A pin	Berg header pin
Header J1
A01	L	Fast	BH1	J1-B
A00	L	Fast	BH2	J1-D
A03	L	Fast	BJ1	J1-F
A02	L	Fast	BJ2	J1-J
A05	L	Fast	BK1	J1-L
A04	L	Fast	BK2	J1-N
A07	L	Fast	BL1	J1-R
A06	L	Fast	BL2	J1-T
A09	L	Fast	BM1	J1-V
A08	L	Fast	BM2	J1-X
A11	L	Fast	BN1	J1-Z
A10	L	Fast	BN2	J1-BB
A13	L	Fast	BP1	J1-DD
A12	L	Fast	BP2	J1-FF
A15	L	Fast	BR1	J1-JJ
A14	L	Fast	BR2	J1-LL
A17	L	Fast	BS1	J1-NN
A16	L	Fast	BS2	J1-RR
C1	L	Fast	BT2	J1-TT
Ground	N/A	N/A	N/A	J1-VV
Header J2
D00	L	Fast	AC1	J2-B
D02	L	Fast	AD1	J2-D
D01	L	Fast	AD2	J2-F
D04	L	Fast	AE1	J2-J
D03	L	Fast	AE2	J2-L
D06	L	Fast	AF1	J2-N
D05	L	Fast	AF2	J2-R
D08	L	Fast	AH1	J2-T
D07	L	Fast	AH2	J2-V
D10	L	Fast	AJ1	J2-X
D09	L	Fast	AJ2	J2-Z
D12	L	Fast	AK1	J2-BB
D11	L	Fast	AK2	J2-DD
D14	L	Fast	AL1	J2-FF
D13	L	Fast	AL2	J2-JJ
PA	L	Fast	AM1	J2-LL
D15	L	Fast	AM2	J2-NN
PB	L	Fast	AN2	J2-RR
Ground	N/A	N/A	N/A	J2-TT
AC LO	L	Slow	BF1	J2-VV
Header J3
NPR	L	Fast	AS2	J3-B
NPG	H	Grant	AU1	J3-D
BR7	L	Fast	AT2	J3-F
BG7	H	Grant	AV1	J3-J
BR6	L	Fast	AU2	J3-L
BG6	H	Grant	BA1	J3-N
BR5	L	Fast	BC1	J3-R
BG5	H	Grant	BB1	J3-T
BR4	L	Fast	BD2	J3-V
BG4	H	Grant	BE2	J3-X
INIT	L	Fast	AA1	J3-Z
BBSY	L	Fast	AP2	J3-BB
Ground	N/A	N/A	N/A	J3-DD
INTR	L	Fast	AB1	J3-FF
SSYN	L	Fast	BU1	J3-JJ
MSYN	L	Fast	BV1	J3-LL
C0	L	Fast	BU2	J3-NN
Ground	N/A	N/A	N/A	J3-RR
SACK	L	Fast	AR2	J3-TT
DC LO	L	Slow	BF2	J3-VV