The IBM 4704

In 2011, while consulting with fellow enthusiasts of IBM keyboards, I was introduced to the keyboards for the IBM 4704 display terminal. This is the terminal for the IBM 4700 Finance Communication System, introduced at the beginning of the 1980s. This page details the information and resources I have been able to find about this system, notably surrounding 4704 terminals for this system and repurposing 4704 input peripherals for modern computers.

This page is dedicated to Nate Walter, known online as SmallFry, who was robbed of his promising life at the young age of 16, 2013-06-27. I’ve really dragged my heels on putting this project live on my site, and I’m very sad that Nate didn’t get a chance to see this published live. If you’re out there somewhere buddy…I’m so sorry. -kishy 2013-07-10

This page is written by a hobbyist for the benefit of hobbyists. I do not claim to be an expert on the topic, and welcome any additional information or corrections (use the Contact option on the menu).

4700 System Overview

The IBM 4700 Finance Communication System is, when boiled down to the basics, a mainframe-terminal arrangement designed to be used primarily for financial transactions (such as in a bank, with each teller having a terminal). This system dates to as early as 1981, and was discontinued by the early 1990s.

IBM 4700 B-loop

An example of a 4700 B-loop, downstream of the 4702 processor.

Terminal connectivity is established via a “B-loop”. This loop connects terminals and other 4700 equipment you’d find at that ‘branch’ with controller equipment which handles uplink-type communications to the mainframe which may be off-site. A number of IBM mainframe systems were supported.

IBM documentation suggests the 4700 local loop connectivity is compatible with their prior financial system, the 3600. At least some 4700 equipment can connect to a 3600 local loop, and vice-versa.

The 4704 Display Terminal

The ‘terminal’ used in a 4700 setup is the 4704. PC, XT, AT and PS/2 computers had options to enable them to act as a 4704, similar in concept to a 3270 PC.


From IBM:

The 4704 is a modular, user configurable CRT display and keyboard terminal for input and output in interactive banking applications. It provides flexibility in both workstation layout and configurations, and can be tailored to meet the needs of teller, back-office and self-service applications.

Stated features of all models of 4704 include:

  • 3604 compatibility
  • Upper and lower case characters
  • Normal and high intensity
  • Adjustable brightness and contrast
  • Audible alarm

All models of 4704 consist of the same basic elements:

  • Display Control Module: the 4704 unit itself
  • CRT monitor, varying by model, integrated within the 4704-3
  • one or more keyboards, varying by model
  • optionally, additional accessories such as magstripe card readers or PIN pads

Model Differences


  • First shipped in October 1982 with 50-key keyboard (62 and 77 came in December 1982)
  • Serial numbers 49999 and down
  • Connects to 4700, 3600/5995 controllers via B-loop
  • Sold with one of two monitors: 5.5″ 480-character (12 lines of 40), or 9″ 480/1920-character (24 lines of 80). These monitors are available with either a 15-degree tilt stand/riser, or an optional adjustable -30 to +30 degree cradle. Anti-glare filters available and display can either be monochrome yellow on brown, or bright green on dark green. Character display is a 7×9 dot matrix.
  • Sold with 50-key Function, 62-key Alphameric, or 77-key Expanded Alphameric keyboard. 50 and 62 can be used in conjunction with each other.
  • It is compatible with the magnetic stripe reader and PIN keypad.
  • Connectors: local loop interface on a permanently attached cable, female DA15 on a permanently attached cable for combined signal and power to the monitor, female DA15 on the unit (purpose presently unknown), C14 normal computer power cord connector, 3x female DE9 for keyboard(s) and accessories
  • Replaced by Model 1 Enhanced

4704-1 Enhanced

  • Replaced original Model 1 as of May 18 1984 – serial numbers 50000 and up with ‘A’ on the tag
  • Similar appearance but different dimensions compared to original Model 1: 260x222x146mm new, 259x208x137mm old
  • Same features as original Model 1, but adds support for the 107-key administrative keyboard and displaying which of four shift modes the keyboard is operating in.


  • First shipped December 1983
  • Similar to 4704-1 with the following differences:
  • Was available for purchase with all four keyboards
  • 3 indicator lights vs the original unit’s 1
  • Connects to 4701 System Controller via coax cable to Device Cluster Adapter (DCA)
  • Two modes of operation: key tracking in the controller, or key tracking locally in the terminal (can relieve load on controller)
  • Supports alerts via Communications Network Management
  • 3278-2 compatibility on the 4701 DCA
  • 3604 and 4704-1 application code can be migrated to the 4704-2 when key tracking is performed in the 4701 controller.
  • Adds feature of operator selectable cursor


  • First shipped December 1983
  • Compatible with 4704-2, except 12″ CRT is integrated. 480 (12 lines of 40) or 1920 (24 lines of 80) characters

What appears to be a 4704-3 from an IBM document

Pictures below are of my own 4704-1:

New October 2013: I now have a 4704 monitor! I have yet to hook up the system and see what it does; likely a blank screen since there’s no loop. Part number is 6019176, manufactured 06-1984. Model designation is “100” and it was made in Japan.

4704 Keyboards

The following keyboards exist for the 4704:

  • 50-key “function”, matrix/grid, relegendable transparent keycaps, designated “Model 100”
    From IBM: “The 50-key Function keyboard is intended for teller use. Forty-five of the keys may have functions assigned by the user. These keys are clear plastic capped to enable labelling by the user. The remaining five keys are pre-engraved. The 50-key keyboard may be used alone or in conjunction with a 62-key keyboard for device functions.”
  • 62-key “alphameric”, designated “Model 200”
    From IBM: “The 62-key alphameric keyboard is intended for use by teller, back-office or administrative personnel. It may be used alone or in conjunction with the function keyboard (above). This keyboard provides full alphameric input plus limited user assigned function.”
  • 77-key “extended alphameric”, designated “Model 300”
    From IBM: “The 77-key expanded alphameric keyboard can be used in any bank function. It provides the same input capability as the alphameric keyboard but also provides a 15-key keypad on the right side of the keyboard. These 15 keys have user assigned functions and are clear-plastic capped for labelling purposes.”
  • 107-key “administrative”, designated “Model 400”

To see additional details of the keyboards which I do own myself, refer to My IBM 4704 Keyboards.

In each case, the keyswitch mechanism is capacitive buckling springs. They are one of, if not the earliest example of an IBM buckling spring keyboard with “relegendable” (transparent plastic) keycaps. While not confirmed, it is possible that the 50-key 4704 keyboard is the only matrix-layout capacitive buckling spring keyboard.

For Personal System/2 computers equipped to provide 4704 emulation, there is a 50-key membrane buckling spring keyboard with native PS/2 connectivity.

The 62-key unit is nicknamed “Kishsaver” by some on account of me introducing a subset of the Geekhack community to this keyboard.

4704 Keyboard Interface

4704 keyboards (and possibly other input peripherals) communicate with a protocol that is approximately similar to, but not the same as XT keyboards. The exact technical details of this protocol are still being investigated.

The physical connector is a male DE with only 4 populated pins (2, 3, 4, 5), carrying clock, data, +5VDC and GND (not in that order – I’ve lost my pinout documentation. If attempting to probe this board, until I can confirm this info, identify +5V and GND first).

At present, the most feasible conversion method for the keyboards to work on modern systems appears to be controller replacement. There is a replacement capacitive sensing controller project which should be adaptable to these keyboards once finished. There is also a project to replace or bypass the existing controller chip with a Teensy or other USB-based development board.

As of July 2013 it is not yet possible to use 4704 keyboards on a typical modern computer via any type of interface.

Other 4704 Peripheral Devices

Other devices which can attach directly to a 4704 include:

  • Magnetic stripe reader (ANSI Track 2, 75 bpi)
  • PIN keypad (12-key numeric keypad)

List of 4700-Series Equipment

Although I am not focusing on any other 4700 series equipment, here is a list of what I’ve been able to find and confirm, between Wikipedia, miscellaneous search results and IBM announcement letters:

  • IBM 4701 — Branch Controller (8″ floppy disc)
  • IBM 4702 — Branch Controller (5-1/4″ HD floppy disc; hard disc)
  • IBM 4704 — Teller Terminal (Keyboard/Magnetic Swipe/Display/Optional PINpad)
  • IBM 4710 — Journal/Cutform Printer
  • IBM 4712 — Journal/Cutform Printer
  • IBM 4713 — Verification Printer
  • IBM 4715 — Printer
  • IBM 4720 — Cutform/Passbook Printer
  • IBM 4722 — Passbook Printer
  • IBM 4723 — Document Processor
  • IBM 4730 — Counter-style Personal Banking Machine (PBM); 1983
  • IBM 4731 — In-lobby PBM; 1983
  • IBM 4732 — In-lobby PBM; 1987
  • IBM 4736 — Cash-only PBM
  • IBM 4737 — Self-service transaction station
  • IBM 4781 — Table Top ATM; 1991 (re-badged Diebold 1060)
  • IBM 4782 — In-lobby ATM; 1991 (re-badged Diebold 1062)
  • IBM 4783 — Cash-only ATM; 1991 (re-badged Diebold 1064)
  • IBM 4785 — Exterior ATM; 1991 (re-badged Diebold 1072)
  • IBM 4786 — Exterior Cash-only ATM; 1991 (re-badged Diebold 1071)
  • IBM 4787 — Exterior Drive-up ATM; 1991 (re-badged Diebold 1073)
  • IBM 4788 — Exterior Self-standing Cash-only ATM; 1991 (re-badged Diebold 1074)
  • IBM 4789 — Cash-only ATM; 1991 (re-badged Diebold 1063)

Where can I find 4700 equipment?

As with most obsolete/EOL computer equipment, there are thousands of parts resellers online and in brick and mortar warehouses promising they can source these systems and parts. However, it is usually the case that they do not have inventory, and far too often they do not have a reliable connection to source these items either. When a reseller will not divulge a price without you submitting a “request for quote” or “request for price” it generally means they don’t have the item and will go looking for it per your request.

I fairly regularly receive requests for information on where someone might buy this equipment. I do not know anymore. The sources that used to have these items do not any longer, and I have not actively sought them since 2014.

If you are, or know of a supplier with real 4700-related inventory in-stock and would like me to list you here, feel free to contact me. You may receive a lot of inquiries from a referral on this page. All I ask in return is information or photos that I don’t already have (parts or accessories are cool too).

Additional Resources and Information


Thanks go out to the following for contributing to this project (in no specific order):

  • dw_junon for introducing me to the 4700 and the keyboards for the 4704
  • Computer Parts Alliance for selling my first (62-key) 4704 keyboard so cheaply, answering questions and providing photos (as well as giving permission to use those photos)
  • Brad at (company withheld) for arranging international shipment of a 107-key 4704 keyboard, providing photos and answering questions
  • Many other sources of information that I neither remember or made a note of.