The Data General Eclipse line of computers by Data General were

16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...

minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

s released in early 1974 and sold until 1988. The Eclipse was based on many of the same concepts as the Data General Nova, but included support for

virtual memory In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very ...

and multitasking more suitable to the small office than the lab. It was also packaged differently for this reason, in a floor-standing case the size of a small refrigerator. The Eclipse series was supplanted by the 32-bit Data General Eclipse MV/8000 in 1980.

Description

The Data General Nova was intended to outperform the

PDP-8 The PDP-8 is a 12-bit minicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model's lifetime. Its basic design follows the pioneeri ...

while being less expensive, and in a similar fashion, the Eclipse was meant to compete against the larger

PDP-11 The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were so ...

computers. It kept the simple register architecture of the Nova but added a stack pointer which the Nova lacked. The stack pointer was added back to the later Nova 3 machines in 1975 and also used on the later 32-bit Data General Eclipse MV/8000. The AOS

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

was quite sophisticated, advanced compared to the PDP-11 offerings, with

access control list In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on giv ...

s (ACLs) for file protection. Production problems with the Eclipse led to a rash of lawsuits in the late 1970s, after new versions of the machine were pre-ordered by many DG customers and then never arrived. After over a year of waiting, some decided to sue the company, while others simply cancelled their orders and went elsewhere. It appeared that the Eclipse was originally intended to replace the Nova outright, also evidenced by the fact that the Nova 3 series released at the same time was phased out the next year. However, strong continuing demand resulted in the Nova 4, perhaps as a result of the continuing problems with the Eclipse.

Facts

The original Cray-1 system used an Eclipse to act as a Maintenance and Control Unit (MCU). It was configured with two

Ampex Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe History ...

CRTs, an 80 MB Ampex disk drive, a thermal printer, and a 9-track tape drive. Its primary purpose was to download an image of either the

Cray Operating System The Cray Operating System (COS) is a Cray Research operating system for its now-discontinued Cray-1 (1976) and Cray X-MP supercomputers. It succeeded the Chippewa Operating System (shipped with earlier Control Data Corporation CDC 6000 seri ...

or customer engineering diagnostics at boot time. Once booted, it acted as a status and control console via RDOS ''station software''.

References

Minicomputers

Eclipse An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ce ...

16-bit computers {{mini-compu-stub