DR780 High-Performance Channel Interface

The DR780 High-Performance Channel Interface provided a high-performance parallel interface, the DR32 Device Interconnect (DDI), for the VAX-11/780, connected to its Synchronous Backplane Interconnect. The DR32 may be used to connect to high-speed customer equipment; alternatively, two may be used to connect two /780's to each other.

A maximum of one DR780 was supported per machine; it could not be installed in a machine which had a MA780 Multiport Memory Option. The DR780 was implemented on four extended hex cards, which mounted in a custom 6-slot backplane (DEC part number 70-16896-0-0); the backplane mounted in one 'Option Panel Space' in the CPU cabinet. The boards were:

Slot	Board	Acronym	Function
1	M8296	DSC	SBI Control Module
2	M8297	DCB	Control Board
3	M8298	DUP	Microprocessor
4	M8299	DSM	Silo Module

One slot (5) is unused, and one slot (6) is used (on the back of the backplane) to hold a hex M9046 DR780 Paddle Card, which carries the DR780 input/output on three BC06R flat cables to an 'External I/O Panel' in the back of the cabinet. From there, a BC06V cable connects to the user equipment.

See also

• DR750 Parallel Interface

Further reading

• DR780 User's Guide (EK-DR780-UG) - not available online
• DR780 Technical Description (EK-DR780-TD) - ditto
• DR780 Field Maintenance Print Set (MP00835)

External links

• Modular Approach to Systems Test - contains a section on the DR780 (on pp. 3-20 of the PDF); includes detailed installation instructions
• VAX-11/780 Installation Manual (EK-SI780-IN-002) - contains a section on the DR780 (on pp. 53-62 of the PDF)
• Dual RK07 Disk-Based VAX-11/780 System Configuration - contains a brief description of the DR780
• RP06/TE16 and RP06/TU77 Based VAX-11/780 System Configuration - ditto