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IBM remote batch terminals

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The IBM 2780[1] and the IBM 3780[2] are devices developed by IBM to perform remote job entry (RJE) functions. They communicate with the mainframe via Binary Synchronous Communications (BSC or Bisync).

2780 Data Transmission Terminal

The 2780 Data Transmission Terminal first shipped in 1967.[3] It consisted of:

  • A line printer similar to the IBM 1443[4] that could 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, that could read up to 400 cards per minute (cpm) and could punch up to 355 cpm.
  • A line buffer that stored data recovered or to be transmitted over the communications line.
  • A binary synchronous adapter which controls the flow of data over the communications line.

The 2780 was capable of local (offline) card to print operation.

It came in four models:[5]

  • Model 1: could read punched cards and transmit the data to a remote host computer, 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: Could only print data received from the host, but not send data to it.
  • Model 4: Could read and punch card data, but had no printing capabilities.

The 2780 used a dedicated communication line at speeds of 1200, 2000, 2400 or 4800 bits per second. It was a half duplex device, although full duplex lines could be used with some increase in throughput. It could communicate in Transcode (a 6-bit code), 8-bit EBCDIC, or 7-bit ASCII.

3780 Data Communications Terminal

The IBM 3780 was an enhanced version of the 2780, that looked physically similar and was announced in May 1972.[6] The 3780 was developed by IBM's Data Processing Division (DPD).[7] The major difference was the lack of models. There was effectively one model, with an optional card punch.

The 3780 dropped Transcode support and incorporates several performance enhancements. It supported compression of blank fields in data using run-length encoding. It provided the ability to interleave data between devices, introduced double buffering, and added support for the Wait-before-transmit ACKnowledgement (WACK) and Temporary Text Delay (TTD) Binary Synchronous control characters.[8]

  • The integrated punched card unit could read cards at 600 cards per minute and punch cards at 160 columns per second.
  • The integrated printer was rated at 300, 350 or 425 lines per minute based on characters set (63, 52 or 39 characters).[9]
  • The 3781 Card Punch was an optional feature. It could output approximately 91 cards per minute.

These devices were later emulated on various types of equipment, including eventually the personal computer. A notable early emulation was the DN60, by Digital Equipment Corporation in the late 1970s.[10]

2770

A similar device, the 2770, announced in 1969, "was said to surpass all other IBM terminals in the variety of available input-output devices."[11] The 2770 can attach the 2213 Printer, the 2502 Card Reader, the 545 Card Punch, the 2265 Display Station, the 1017 Paper Tape Reader, the 1018 Paper Tape Punch, the 50 Magnetic Data Inscriber, and the 1255 Magnetic Character Reader. The printer and devices for any two other media can be attached to one 2772 Control Unit.[12] The 2770 was developed by the IBM General Products Division (GPD) in Rochester, MN.[13]

3770 Data Communications System

In 1974[14] IBM Data Processing Division (DPD) offered a successor, called the 3770 Data Communications System, that supported SDLC, BSC, BSC Multi-leaving and SNA, depending on the configuration. The 3770 was a family of desk console style terminals that offered a variety of keyboard and printer combinations as well as I/O equipment attachment and communications features.

The terminals literally came built into a desk with an integrated 10 CPI printer (except the 3777 which had a standalone chain printer), and included the following models:[5]

  • 3771 Communication Terminal Models 1, 2, and 3
  • 3773 Communication Terminal Models 1, P1, 2, P2, 3, and P3
  • 3774 Communication Terminal Models I, P1, 2, and P2
  • 3775 Communication Terminal Models 1 and P1
  • 3776 Communication Terminal Models 1 and 2
  • 3777 Communication Terminal Model 1 (used a standalone printer)

Models with a P designation are user programmable for one or more operations.

The following I/O devices could also 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 allowed the 2502 or 3521 to be attached to any terminal except the 3777
  • IBM 3784 Line Printer, could be attached to a 3774 as a second printer. Up to 155 LPM with 48 characters set print belt.

Notes

  1. ^ picture of an IBM 2780
  2. ^ picture of an IBM 3780
  3. ^ IBM Corporation. "Rochester chronology". Retrieved June 3, 2012.
  4. ^ IBM 1443 printer description
  5. ^ a b IBM System/370 System Summary. http://www.bitsavers.org/pdf/ibm/370/systemSummary/GA22-7001-6_370_System_Summary_Dec76.pdf: IBM. 1976. pp. 8–40. {{cite book}}: External link in |location= (help)CS1 maint: location (link)
  6. ^ "IBM Archives: DPD chronology, page 4". IBM. Retrieved 2007-01-18.
  7. ^ "IBM Archives: DPD Chronology". Retrieved June 24, 2012.
  8. ^ Hewlett Packard. "RJE/XL Node Manager's Guide". Retrieved June 7, 2012.
  9. ^ IBM Corporation (1979). IBM Sales Manual: DP Machines (PDF).
  10. ^ Maintenance manual for the DN60 series, includes an overview of BISYNC
  11. ^ Pugh; et al. (1991). IBM's 360 and Early 370 Systems. The MIT Press. ISBN 0-262-16123-0.
  12. ^ IBM Corporation. IBM Field Engineering Announcement: The IBM 2770 Data Communication System (PDF).
  13. ^ "IBM Archives: Rochester Chronology". Retrieved June 24, 2012.
  14. ^ Frank, Ronald A. (June 25, 1975). "IBM 3770 Performance, Savings, Please Service Firm". Computerworld. Retrieved June 23, 2012.

References

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