1977

The introduction of semiconductor memory in the early 1970s, and especially dynamic RAM shortly thereafter, led to dramatic reductions in the price of memory as the effects of Moore's Law were felt. Within years, it was common to equip a machine with all the memory it could address, typically 64 KB on 16-bit machines.
This led vendors to introduce new designs with the ability to address more memory, often by extending the address format to 18 or 24 bits in machines that were otherwise similar to their earlier 16-bit designs. In contrast, DEC decided to make a more radical departure. In 1976, they began the design of a machine whose entire architecture was expanded from the 16-bit PDP-11 to a new 32-bit basis. This would allow the addressing of very large memories, which were to be controlled by a new virtual memory system, and would also improve performance by processing twice as much data at a time. The system would, however, maintain compatibility with the PDP-11, by operating in a second mode that sent its 16-bit words into the 32-bit internals, while mapping the PDP-11's 16-bit memory space into the larger virtual 32-bit space.
The result was the VAX architecture, where VAX stands for Virtual Address eXtension (from 16 to 32 bits). The first computer to use a VAX CPU was the VAX-11/780, announced in October 1977, which DEC referred to as a superminicomputer. Although it was not the first 32-bit minicomputer, the VAX-11/780's combination of features, price, and marketing almost immediately propelled it to a leadership position in the market after it was released in 1978. VAX systems were so successful that in 1983, DEC canceled its Jupiter project, which had been intended to build a successor to the PDP-10 mainframe, and instead focused on promoting the VAX as the single computer architecture for the company.
Supporting the VAX's success was the VT52, one of the most successful smart terminals. Building on earlier less successful models, the VT05 and VT50, the VT52 was the first terminal that did everything one might want in a single inexpensive chassis. The VT52 was followed by the even more successful VT100 and its follow-ons, making DEC one of the largest terminal vendors in the industry. This was supported by a line of inexpensive computer printers, the DECwriter line. With the VT and DECwriter series, DEC could now offer a complete top-to-bottom system from computer to all peripherals, which formerly required collecting the required devices from different suppliers. The VAX processor architecture and family of systems evolved and expanded through several generations during the 1980s, culminating in the NVAX microprocessor implementation and VAX 7000/10000 series in the early 1990s.

March:
DIGITAL announces a new mid-range price/performance system, the PDP-11/60.
The PDP-11/60 offered a combination of unique attributes, which were normally found in larger, more expensive computers at the time. Designed around the proven UNIBUS architecture, the PDP-11/60 included user control store features previously unavailable from DIGITAL as well as several 11/70 class features such as cache memory and RAMP.

May:
DIGITAL announces its newest computer, the DECstation, a family of components centered around the VT78 Video Data Processor. The DECstation was a complete PDP-8 computer system implemented in large scale integration technology so that it could be packaged inside the shell of a display terminal. Designed for an interactive environment, the primary emphasis was on system capability, hence the large 16K (32Kb) memory and the array of I/O controllers.

October:
Introduction of the VAX-11/780, the first member of the VAX computer family.
VAX-11 architecture was designed to alleviate the PDP-11's most severe limitation: an address space that was too small for many applications. The Virtual Address eXtension (VAX) increased the address from 16 to 32 bits. The number of general registers also doubled from 8 to 16. The instruction set had both two and three operand formats for many common operations with either a register or memory operand allowable.

DIGITAL is the first computer company to connect to the ARPAnet. The connection is made via a PDP-10. In 1969, the U.S. Defense Department’s Advanced Research Projects Agency (ARPA) began to construct a resource sharing computer network among its contractors. This network became known as the ARPAnet, a wildly successful wide-area packet switching network that later evolved into the Internet. By 1970, the initial four-node configuration was complete consisting of UCLA, UC Santa Barbara, Stanford Research Institute and the University of Utah. From these four sites, the network expanded to thirteen by January 1971 and twenty-three by April 1972. By the time that DIGITAL joined as the first computer company in 1977, there were approximately 60 nodes in operation.

1978

Last update 29-03-2026 ... to be continued ...