GE-200 series
Encyclopedia
The GE-200 series was a family of small mainframe
computer
s of the 1960s, built by General Electric
.
The main machine in the line was the GE-225. It used a 20-bit word, of which 13 bits could be used for an address. Along with the basic CPU
the system could also include a floating-point
unit, or interestingly, a fixed-point
decimal option with three 6-bit decimals per word. It had 11 I/O
channel controllers, and GE sold a variety of add-ons including disks, printers and other devices. The machines were built using discrete transistors, with a typical machine including about 10,000 transistors and 20,000 diodes. They used core memory, and a standard 8k-word system held 186,000 magnetic cores.
The GE-215 was a scaled-down version of the GE-225, including only 6 I/O channels and only 4K or 8K of core.
The GE-235 was a re-implementation of the GE-225 with three times faster memory than the original.
The GE-235 consisted of several major components and options:
Through the early 1960s GE worked with Dartmouth College
on the development of a time-sharing
operating system
, which would later go on to become Dartmouth Time Sharing System
(DTSS). The system was constructed by attaching a number of teletypewriters to a smaller GE machine called the Datanet-30, which was a small computer that had evolved from an earlier process-control machine.
DTSS was an odd system; it didn't run on the GE-235, but the DN-30 instead. The DN-30 accepted commands one at a time from the terminals connected to it, and then ran their requested programs on the GE-235. The GE-235 had no idea it was not running in batch mode, and the illusion of multitasking
was being maintained externally.
In 1965 GE started packaging the DN-30 and GE-235 systems together as the GE-265. The GE-265 achieved fame not only for being the first commercially successful time-sharing system, but it was also the machine on which the BASIC programming language was first created.
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s of the 1960s, built by General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
.
The main machine in the line was the GE-225. It used a 20-bit word, of which 13 bits could be used for an address. Along with the basic CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
the system could also include a floating-point
Floating point
In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...
unit, or interestingly, a fixed-point
Fixed-point arithmetic
In computing, a fixed-point number representation is a real data type for a number that has a fixed number of digits after the radix point...
decimal option with three 6-bit decimals per word. It had 11 I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
channel controllers, and GE sold a variety of add-ons including disks, printers and other devices. The machines were built using discrete transistors, with a typical machine including about 10,000 transistors and 20,000 diodes. They used core memory, and a standard 8k-word system held 186,000 magnetic cores.
The GE-215 was a scaled-down version of the GE-225, including only 6 I/O channels and only 4K or 8K of core.
The GE-235 was a re-implementation of the GE-225 with three times faster memory than the original.
The GE-235 consisted of several major components and options:
- Central processor
- 400 CPM or 1000 CPM card reader
- 100 CPM card punch or 300 CPM card punch
- Perforated tape subsystem
- Magnetic tape subsystem
- 12 Pocket high-speed document handler
- On-line high speed printer or Off/on-line speed printer
- Disc storage unit
- Auxiliary Arithmetic Logic Unit (ALU)
- DATANET data communications equipment
Through the early 1960s GE worked with Dartmouth College
Dartmouth College
Dartmouth College is a private, Ivy League university in Hanover, New Hampshire, United States. The institution comprises a liberal arts college, Dartmouth Medical School, Thayer School of Engineering, and the Tuck School of Business, as well as 19 graduate programs in the arts and sciences...
on the development of a time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
, which would later go on to become Dartmouth Time Sharing System
Dartmouth Time Sharing System
The Dartmouth Time-Sharing System, or DTSS for short, was the first large-scale time-sharing system to be implemented successfully. DTSS was inspired by a PDP-1-based time-sharing system at Bolt, Beranek and Newman. In 1962, John Kemeny and Thomas Kurtz at Dartmouth College submitted a grant for...
(DTSS). The system was constructed by attaching a number of teletypewriters to a smaller GE machine called the Datanet-30, which was a small computer that had evolved from an earlier process-control machine.
DTSS was an odd system; it didn't run on the GE-235, but the DN-30 instead. The DN-30 accepted commands one at a time from the terminals connected to it, and then ran their requested programs on the GE-235. The GE-235 had no idea it was not running in batch mode, and the illusion of multitasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
was being maintained externally.
In 1965 GE started packaging the DN-30 and GE-235 systems together as the GE-265. The GE-265 achieved fame not only for being the first commercially successful time-sharing system, but it was also the machine on which the BASIC programming language was first created.
See also
- GE-600 seriesGE-600 seriesThe GE-600 series was a family of 36-bit mainframe computers originating in the 1960s, built by General Electric . When GE left the mainframe business the line was sold to Honeywell, who built similar systems into the 1990s as the division moved to Groupe Bull and then NEC.-Architecture:The 600...
- The GE-400 a high maintenance system that pre-dated the GE-600