The IBM 2780 and the IBM 3780 are devices developed by
IBM to perform
remote job entry (RJE) and other batch functions over telephone lines; they communicate with the
mainframe via
Binary Synchronous Communications
Binary Synchronous Communication (BSC or Bisync) is an IBM character-oriented, half-duplex link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous transmit-receive (STR) protocol used with second gene ...
(BSC or Bisync) and replaced older terminals using
synchronous transmit-receive
Synchronous transmit-receive (STR) was an early IBM character-oriented communications protocol which preceded Bisync. STR was point-to-point only, and employed a ''four-of-eight'' transmission code, communicating at up to 5100 characters per se ...
(STR). In addition, IBM has developed workstation programs for the
1130,
360/20,
2922,
System/360 other than 360/20,
System/370
The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path f ...
and
System/3
The IBM System/3 was an IBM midrange computer introduced in 1969, and marketed until 1985. It was produced by IBM Rochester in Minnesota as a low-end business computer aimed at smaller organizations that still used IBM 1400 series computers or u ...
.
2780 Data Transmission Terminals
The 2780 Data Transmission Terminal first shipped in 1967. It consists of:
* A
line printer
A line printer prints one entire line of text before advancing to another line. Most early line printers were
impact printers.
Line printers are mostly associated with unit record equipment and the early days of digital computing, but the ...
similar to the IBM 1443 that can print up to 240 lines per minute (lpm), or 300 lpm using an extremely restricted character set.
* A card reader/punch unit, similar to an
IBM 1442
IBM 1442 is a combination IBM card reader and card punch. It reads and punches 80-column IBM-format punched cards and is used on the IBM 1440, the IBM 1130, the IBM 1800 and System/360 and is an option on the IBM System/3.
Overview
The 1442 ca ...
, that can read up to 400 cards per minute (cpm) and can punch up to 355 cpm.
* A line buffer that stores data received or to be transmitted over the communications line.
* A binary synchronous adapter which controls the flow of data over the communications line.
The 2780 is capable of local (offline) card to print operation.
It comes in four models:
* Model 1: Can read
punched cards
A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to d ...
and transmit the data to a remote
host computer
A network host is a computer or other device connected to a computer network. A host may work as a Server (computing), server offering information resources, services, and applications to users or other hosts on the network. Hosts are assigned at ...
, and can receive and print data sent by the host.
* Model 2: Same as Model 1 but adds the ability to punch card data received from the host.
* Model 3: Can only print data received from the host, but not send data to it.
* Model 4: Can read and punch card data, but has no printing capabilities.
The 2780 uses a dedicated communication line at speeds of 1200, 2000, 2400 or 4800 bits per second. It is a
half duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
device, although
full duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
lines can be used with some increase in throughput. It can communicate in ''
Transcode
Transcoding is the direct digital-to-digital conversion of one encoding to another, such as for video data files, audio files (e.g., MP3, WAV), or character encoding (e.g., UTF-8, ISO/IEC 8859). This is usually done in cases where a target devic ...
'' (a 6-bit code), 8-bit ''
EBCDIC
Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six- ...
'', or 7-bit ''
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
''.
2770 Data Communication System
The 2770, announced in 1969, ''"was said to surpass all other IBM terminals in the variety of available input-output devices.''" The 2770 was developed by the IBM General Products Division (GPD) in Rochester, MN.
It comes standard with a desktop terminal with keyboard. The printer and other devices (any two in any combination) can be attached to the 2772 Multi-Purpose Control unit. Possible devices include:
* 50 Magnetic Data Inscriber
* 545 Card Punch Model 3 (non-printing) or Model 4 (printing)
* 1017 Paper Tape Reader
* 1018 Paper Tape Punch
* 1053 Printer Model 1
* 1255 Magnetic Character Reader Models 1, 2 or 3
* 2203 Printer Model A1 or A2
* 2213 Printer Model 1 or 2
* 2265 Display Station Model 2
* 2502 Card Reader Model A1 or A2
* 5496 Data Recorder
3780 Data Communications Terminal
In May 1972, IBM announced the IBM 3780, an enhanced version of the 2780. The 3780 was developed by IBM's Data Processing Division (DPD). There is one model, with an optional card punch.
The 3780 drops Transcode support and incorporates several performance enhancements. It supports compression of blank fields in data using
run-length encoding
Run-length encoding (RLE) is a form of lossless data compression in which ''runs'' of data (sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original ...
. It provides the ability to interleave data between devices, introduces
double buffering
In computer science, multiple buffering is the use of more than one buffer to hold a block of data, so that a "reader" will see a complete (though perhaps old) version of the data, rather than a partially updated version of the data being creat ...
, and adds support for the Wait-before-transmit ACKnowledgement (WACK) and Temporary Text Delay (TTD) Binary Synchronous control characters.
* The integrated punched card unit can read cards at 600 cards per minute.
* The integrated printer is rated at 300, 350 or 425 lines per minute based on characters set (63, 52 or 39 characters).
* The 3781 Card Punch is an optional feature. It punches 160 columns per second, or 91 cards per minute if all 80 columns are punched.
The IBM 2780 and 3780 were later
emulated
In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run so ...
on various types of equipment, including eventually the
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
. A notable early emulation was the DN60, by
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...
in the late 1970s.
3770 Data Communications System
In 1974 IBM Data Processing Division (DPD) offered a successor to the 3780, called the 3770 Data Communications System, supporting SDLC, BSC, BSC Multi-leaving
[
] and
SNA, depending on the configuration. The 3770 is a family of desk console style terminals that offers a variety of keyboard and printer combinations as well as I/O equipment attachment and communications features.
The terminals come built into a desk and include the following models:
* 3771 Communication Terminal (optional card reader, optional card punch, wire matrix printer) Models 1 (40 cps printer), 2 (80 cps printer), and 3 (120 cps printer).
* 3773 Communication Terminal (diskette, wire matrix printer) Models 1 (40 cps printer), 2 (80 cps printer), and 3 (120 cps printer). Each model has a P version which adds some programming features.
* 3774 Communication Terminal (optional card reader, optional card punch, optional belt printer, wire matrix printer) Models 1 (80 cps printer), and 2 (120 cps printer). Each model has a P version which adds some programming features, a 480-character display and a non-removable diskette.
* 3775 Communication Terminal (optional card reader, optional card punch, optional diskette, belt printer) Model 1 (120 lpm printer). The model P1 adds some programming features, a 480-character display and a non-removable diskette.
* 3776 Communication Terminal (optional card reader, optional card punch, optional diskette, belt printer) Models 1 (300 lpm printer) and 2 (400 lpm printer). Models 3 and 4 are similar to models 1 and 2.
* 3777 Communication Terminal (optional card reader, optional diskette, train printer) Model 1 (up to 1000 lpm printer depending on character set). Model 2 adds an optional card punch, model 3 adds an optional magnetic tape drive and model 4 replaces the train printer with a slower model called the IBM 3262. The model 4 also allows a second, optional, 3262.
The following I/O devices can be attached to a 3770 terminal:
* IBM 2502 Card Reader: Models A1 (up to 150 card per minute), A2 (up to 300 cards per minute) or A3 (up to 400 cards per minute)
* IBM 3203 Printer Model 3: 1000 LPM using 48 character set
* IBM 3501 Card Reader: Up to 50 cards per minute desktop unit
* IBM 3521 Card Punch: Up to 50 cards per minute
* IBM 3782 Card Attachment unit, which allows the 2502 or 3521 to be attached to any terminal except the 3777
* IBM 3784 Line Printer, can be attached to a 3774 as a second printer. Up to 155 LPM with 48 characters set print belt.
Workstation programs
IBM distributes workstation programs with systems software including
*
OS/360
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB ...
*
Attached Support Processor
Attached Support Processor (ASP) was an implementation of loosely coupled multiprocessing for IBM's OS/360 operating system. IBM later changed the name to Asymmetrical multiProcessor but retained the acronym ASP.
ASP evolved from the design of t ...
(ASP)
*
Houston Automatic Spooling Priority
The Houston Automatic Spooling Priority Program, commonly known as HASP, is an extension of the IBM OS/360 operating system and its successors providing extended support for "job management, data management, task management, and remote job entry ...
(HASP and HASP II)
* Operating System/Virtual Storage 1 (
OS/VS1
Operating System/Virtual Storage 1, or OS/VS1, is a discontinued IBM mainframe computer operating system designed to be run on IBM System/370 hardware. It was the successor to the OS/360 and successors#MFT, Multiprogramming with a Fixed number of ...
)
* Operating System/Virtual Storage 2 (
OS/VS2 Operating System/Virtual Storage 2 (OS/VS2) is the successor operating system to OS/360 MVT in the OS/360
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for thei ...
MVS
Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. IBM developed MVS, along with OS/VS1 and SVS, as a successor to OS/360. It is unrelated ...
) Release 2 through 3.8
* MVS versions from MVS/SP Version 1 through
z/OS
z/OS is a 64-bit operating system for IBM z/Architecture mainframes, introduced by IBM in October 2000. It derives from and is the successor to OS/390, which in turn was preceded by a string of MVS versions.Starting with the earliest:
* O ...
* Priority Output Writers, Execution processors and input Readers (
POWER
Power most often refers to:
* Power (physics), meaning "rate of doing work"
** Engine power, the power put out by an engine
** Electric power
* Power (social and political), the ability to influence people or events
** Abusive power
Power may a ...
)
*
Remote Spooling Communications Subsystem Remote Spooling Communications Subsystem or RSCS is a subsystem ("virtual machine" in VM terminology) of IBM's VM/370 operating system which accepts files transmitted to it from local or remote system and users and transmits them to destination loc ...
(RSCS)
Except for the RJE workstation programs in OS/360, these programs use a variation of BSC known as Multi-leaving.
[ In addition, IBM provides separately ordered workstation programs using BSC. ]Systems Network Architecture
Systems Network Architecture (SNA) is IBM's proprietary networking architecture, created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA describes formats and protocols but, in itself, is not a pi ...
(SNA) and TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
.
Workstation programs are available from IBM and third-party vendors to support all of these protocols:
* 2770/3770
* 2780/3780
* Multileaving
* Network Job Entry (NJE)
* OS/360 RJE[
]
* SNA
* TCP/IP
Notes
References
External References
*
*
*
*
*
Images of 2780 and 3780
{{DEFAULTSORT:Ibm 2780 3780
2780
Block-oriented terminal
Computer networks
Job scheduling
Remote job entry