VAX-11/782

VAX-11/782
Summary
Codename:	Atlas
OS support (VMS):	VMS 3.0 to V4.7
CPU Details
Number of processors:	2
CPU technology:	Bipolar Schottky
CPU cycle time:	200ns
Instruction-buffer:	8 bytes [1]
Translation-buffer:	128 entries [1]
Control store:	4K 99-bit words [1]
Gate delay:	3ns
User Writable Control Store:	2K 99-bit words [1]
Cache:	8KB [1]
Compatibility mode:	Yes
Console processor:	LSI-11 [1]
Console device:	RX01 [1]
Memory
Physical address lines:	30
Memory checking:	8-bit ECC/longword [1]
I/O
Max I/O throughput:	11MB/s
LAN support:	optional
Performance
VUPs:	1.8

The VAX-11/782 was an early asymmetric dual processor VAX; it had two KA780 CPUs connected to up to four MA780 multi-port memory units (up to 2 Mbytes of main memory each). All I/O peripherals were attached to the 'master' CPU.

VAX-11/782 Attached-processor System

The VAX-11/782 presented in the "VAX Hardware Handbook Volume 1 - 1986":

The VAX-11/782 attached-processor system is a tightly coupled, asymmetrical multiprocessor system based on a MA780 multiport shared memory. The system can provide up to 1.8 times the performance of the VAX-11/780 system. The VAX-11/782 consists of two VAX-11/780 processors and a 4-Mbyte MA780 shared main memory mounted between the VAX CPU cabinets. The main memory can be expanded to 8 Mbytes by adding a second MA780 multiport memory cabinet containing 4 Mbytes of memory. One VAX-11/780 CPU, designated the primary processor, contains 256 Kbytes of local ECC MOS memory for diagnostics programs, a shared memory interface, and a DW780 Unibus Adapter. All I/O devices and peripheral devices connect to the primary processor. The second CPU is designated the attached processor and contains 256 Kbytes of local memory for diagnostic testing and a shared memory interface. The attached processor does not support I/O devices.

The UNIBUS and MASSBUS adapters and the CI and DDI adapters available for the primary processor are the same as those used with the single VAX-11/780 processor system. The mass storage devices available for the primary processor are also the same as those used with the single VAX-11/780 processor system. The VAX-11/782 processor system cannot be connected to VAXcluster components. A UNIBUS expansion cabinet can be added to the VAX-11/782 system. The FP780 floating-point accelerator option can be added to each VAX-11/780 processor to decrease the execution time of the floating-point operations and some of the integer arithmetic operations.

VAX-11/782 simulator

There is a special SIMH VAX-11/782 simulator with detailed instructions available.

External links

• VAX Hardware Handbook Volume 1 - 1986 (VAX-11/782 on pdf pages 36ff)