DB11-A Bus Repeater

The DB11-A Bus Repeater allows a UNIBUS to double the number of peripherals connected to the bus (in terms of the combined analog load). It terminates the first section of the bus, and active digital logic repeats all the signals though onto the second section (or from the second back to the first, when required); the two sections are thus logically connected, but are not in purely analog terms.

It consists of a custom system unit backplane, holding a number of smaller FLIP CHIPs; mostly singles (see table below), with one dual (M7213).

Type	Count	Function
M783	1	Bus driver
M784	1	Bus receiver
M785	4	Bus transceiver
M7212	3	Address buffer
M7213	1	Buffer master
M7248	1	BBSY repeater
M930	2	UNIBUS terminator

Board locations (as seen from the board insertion side of the backplane, not the wire-wrap pin side, as is common in DEC documentation) are:

	Connector
Slot	A	B	C	D	E	F
1	UNIBUS A In		M7248	M7212	M7212	M7212
2	UNIBUS A termination		Unused		M784	M783
3	Power	Unused	M7213		M785	M785
4	UNIBUS B Out		UNIBUS B termination		M785	M785