IBM banking equipment

Loop connection

A loop in the 3600 system is a closed cable circuit — distinct from telephone lines — in which a controller connects to a series of terminals daisy-chained together, with the final terminal returning to the originating controller. Transmitted data travels around the loop in a single direction. Each device on the loop uses switches to set a terminal address (0 to 15) and the loop speed (either 600, 1200, 2400 or 4800 bits per second). All devices on the loop need to be set to the same speed.^[13]

The following devices were announced as part of the 3600 system:^[7]

IBM 3601 Finance Communication Controller

The IBM 3601 Finance Communication Controller is the programmable control unit at the centre of the 3600 system. It contains up to 40 KB of programmable storage and an integrated data file on a removable diskette for storage of controller data, user programs, and customer data. The controller manages all attached terminal functions, controls data transmission between the terminals and the host processor, and can operate independently when the CPU is unavailable — capturing data from terminals, executing arithmetic operations, and storing transactions on disk for later transmission.^[14]

Key features include:

• One standard loop with up to five additional loops available as special features
• Support for local loops at 1,200, 2,400, or 4,800 bit/s, and remote loops at 1,200 bit/s via integrated modem
• Communication with the host processor over SDLC via an integrated 1,200 bit/s modem or external modems at up to 4,800 bit/s
• Off-line operation with transaction capture and disk-based data storage
• Configuration and Parameter Generation (CPGEN) facilities for defining work station arrangements, keyboard layouts, and device assignments

IBM 3604 Keyboard Display

The IBM 3604 Keyboard Display is an interactive terminal providing input and output for teller work stations. It features a 240-character gas-panel display arranged in six rows of 40 characters, rendered in a 7 × 9 point matrix. A variety of keyboard options are available, including numeric, alphanumeric, and expanded function key layouts. The 3604 can optionally be equipped with a magnetic stripe reader or encoder-reader, enabling it to read credit cards to ABA standards and read or encode magnetic stripe labels on passbooks.^[15]

IBM 3610 Document Printer

The IBM 3610 Document Printer is a compact table-top printer for hard-copy output of banking transactions. It prints at 10 characters per inch across 80 print positions, at speeds of 15 cps (with a 64-character set) or up to 30 cps (with a 96-character set). Three models were announced: Model 1 prints on cut forms only; Model 2 adds a journal/audit roll; and Model 3 prints on continuous fanfold paper. The printer can be shared between two teller stations.^[16]

IBM 3612 Passbook and Document Printer

The IBM 3612 Passbook and Document Printer is a table-top printer with two separate disk print mechanisms — one for passbook printing at 12 characters per inch and the other for cut forms, journal rolls, or continuous forms at 10 characters per inch. The passbook mechanism supports both horizontal-fold and vertical-fold passbooks with a print line of up to 100 characters. As with the 3610, three models were announced covering cut forms, journal rolls, and continuous fanfold paper respectively, and the unit can be shared between two stations.^[17]

IBM 3614 Consumer Transaction Facility

The IBM 3614 Consumer Transaction Facility is an online banking terminal that provides customers with direct, self-service access to their accounts. Introduced in 1973 as IBM's second-generation banking machine and successor to the IBM 2984, the 3614 expanded beyond simple cash dispensing to support balance enquiries, deposits, payments, and other transactions configured by the financial institution.^[6] An optional deposit module enables bill payments alongside standard deposits, and an optional receipt printer provides customers with a printed record of each transaction.^[18]

The terminal connects to a bank's central mainframe computer via telephone lines, which allowed financial institutions to deploy 3614s well beyond traditional branches — including supermarkets, department stores, and other high-traffic retail locations. This off-premises deployment model enabled banks to extend their customer reach without investing in additional branch infrastructure, while retail hosts benefited from customers having ready access to cash. Virginia National Bank notably installed an IBM 3614 in the main concourse of The Pentagon.^[6][19]

Four models of the 3614 are available:

Models 11 and 12 are collectively referred to as Dual Document Feed models.^[18] Announcement and withdrawal dates per IBM Hursley Museum hardware records.^[20]

All 3614 models support the following optional features: transaction statement printer, depository unit, transaction chaining, transaction journaling, and check cashing. The last three — transaction chaining, journaling, and check cashing — are grouped under the designation Expanded Function Features.^[18]

A 40-character display guides customers through each step, prompts correction of any input errors, and returns account information visible only to the account holder. The unit also includes a card retention mechanism for flagging stolen cards, and can trigger an external alarm if tampering is detected.^[21] The through-the-wall models (2 and 12) use a protective window equipped with a safety clutch, which covers the access area (except the card slot). This opens when a card is inserted and closes 25 seconds after the last transaction is made.^[18]

Unusual by today's standards, the customer's ATM card was inserted with the magnetic stripe facing up as can be seen in the informational decal in the image of the IBM 2984. Modern ATMs typically expect customers to insert their card with the stripe facing down, which has the added benefit of displaying the card issuer's logo during insertion.^[22]

The 3614 was withdrawn from marketing on 9 March 1981.^[20]

IBM 3618 Administrative Line Printer

The IBM 3618 Administrative Line Printer is a medium-speed line printer for volume output. It uses a continuous-belt print technology and prints on continuous fanfold paper with up to 80 print positions on an 8-inch line, expandable to 132 positions on a 13.2-inch line with the Expanded Print Line special feature. Print speeds range from 80 lpm (with a 96-character set) to 155 lpm (with a 48-character set). An optional dual independent forms feed enables two different paper sizes to be handled simultaneously.^[23]

IBM 3624 Consumer Transaction Facility

The IBM 3624 was released in 1978 as a second-generation automatic teller machine (ATM) as a successor to the IBM 3614.^[11] Designed at the IBM Los Gatos lab, the IBM 3624 was manufactured at IBM facilities in Charlotte, North Carolina and Havant, England.^[24] The original product announcement of 14 March 1978 listed Raleigh as the plant of manufacture, with first customer shipments scheduled for February 1979.^[25]

The 3624 is an unattended self-service terminal that issues variable amounts of currency, accepts deposits, and performs other financial transactions. It was designed for IBM 3614 family compatibility, allowing coexistence with existing 3614 installations on the same loop and simplifying the transition between the two products.^[25] It attaches to a 3601 or 3602 Finance Communication Controller via a loop interface, or directly to a virtual storage IBM S/370 or IBM 4300 processor through an IBM 3704 or IBM 3705 Communications Controller via SDLC.^[24]

At announcement the purchase prices were US$12,150 for Model 1, US$13,400 for Model 2, US$14,150 for Model 11, and US$15,400 for Model 12.^[25] There were four models:^[26]

The dual-feed models (11 and 12) can issue two different denominations in a single transaction, or load the same denomination in both dispensers to double the bill capacity. Documents other than currency, such as traveller's cheques, can also be dispensed if they pass a qualification test. The machine issues up to 20 bills at a time in a single stack with no pre-packaging.^[25]

Key features include:^[25][24]

• Portable, interchangeable currency cartridges holding approximately 2,300 new bills or 1,700 used bills
• Cash issuing, account balance enquiry, account-to-account transfer, cheque cashing, deposits, and bill payments
• Programmable transaction keys with numeric or alphanumeric keypads
• Keyboard slanted 15 degrees from vertical for privacy; guidance display panel swivel-mounted for visibility and sunshielding
• Walk-up and drive-up configurations on Models 2 and 12
• Multiple language display based on identifier code on the customer's card
• Transaction chaining — multiple transactions with a single card insertion
• Customisable backlighted logo panel extending across the full width of the front

An optional transaction statement printer produces receipts on 96-column card stock measuring 2-5/8 × 3+1⁄4 inches (67 × 83 mm), and can also retain copies within a journal stacker for audit purposes. When making deposits, customers place a transaction record inside a deposit envelope; the optional depository printer stamps a sequence number on each envelope as it passes through the depository throat.^[24]

Models 2 and 12, when installed with the heavy-duty enclosure and through-the-wall accessories, meet the specifications of UL 291 and comply with the intent of U.S. Federal Regulation P for unattended operation when the branch is closed. The lobby models (1 and 11) meet the specifications of UL 114 and comply with the intent of Regulation P for attended use during business hours, on the condition that the machine is empty of currency at all other times.^[25]

An unfortunate design characteristic of the 3624 was that the vault containing the cash dispenser was located in the upper area of the unit, making it top-heavy and extremely awkward to transport up and down stairs.^{[citation needed]} Another common complaint was the relatively small capacity of the currency cartridges compared to competitors' equipment at the time.^{[citation needed]}

As was typical for ATM hardware of this era, the IBM 3624 has two distinct high-level communications protocols. The first, a direct mainframe attachment through SDLC links, is an IBM SNA LU0 protocol. The second is an attachment to the IBM 3600 and 4700 series of banking equipment via a start-stop TDM loop with time slots assigned to specific 36xx series equipment at 1,200 bit/s. The loop interface uses an internal 1,200 bit/s integrated modem for remote attachment.^[24]

The IBM 3612, 3624 and 3600 communications protocols were incompatible with other ATM vendors' high-level communications protocols.^[27]

One of the most lasting features introduced with the 3624 was the IBM 3624 PIN block format used in transmission of an encrypted personal identification number (PIN).^[28][29] The 3624 uses the U.S. Federal Information Processing Data Encryption Standard (DES) algorithm for encryption of sensitive data during communication line transmission. The encryption modules required for the 3600 Host Support program were designated BQKDES and BQKDPRS; source listings were not orderable and were not supplied with these modules.^[25][24]

IBM 4701 Finance Communication Controller and 4702 Processor

The IBM 4701 Finance Communication Controller is the programmable hub of the 4700 system. It is a compact, tabletop unit housing an operating system, customer application programs, and the configuration data that defines the attached work stations. The controller manages all loop-attached terminals and printers, runs application logic — including arithmetic, data formatting, and host communication — and can continue to capture and process transactions locally when the host link is unavailable.

The models included:^[33]

Both 4701 models 1 and 2 include 192 KB of base controller storage(expandable in 64 KB increments to a maximum of 512 KB), an integrated diskette drive, hardware-based Data Encryption Standard (DES) encryption, and a host-computer attachment using SDLC. A software-based system monitor, loaded from diskette, controls operating functions and accepts commands from an attached 4704 display station, replacing the hardware control panels of earlier controllers.^[30]

IBM 4704 Display Station

The IBM 4704 Display Station is the primary operator interface for the 4700 system. All models use a cathode-ray tube (CRT) display with a detached, low-profile keyboard, and accept anti-glare filter panels in two colour options: green characters on a dark green ground, or yellow on brown. Each model can be fitted with a magnetic stripe unit and a personal identification number (PIN) keypad as optional accessories.^[30]

Models offered included:

• Model 1 — announced on 14 September 1981 it is a two-unit modular station suited to teller positions, with a separate display module and control module that can be positioned independently; available with either a 139.7 millimetres (5.50 in) diagonal screen showing 480 characters (12 rows of 40), or a 228.6 millimetres (9.00 in) diagonal screen switchable between 480 and 1,920 characters under program control; attaches to the 4701 via the standard terminal loop^[30]
• Model 2 — announced on 1 February 1983 it is a semi-modular station for administrative positions carrying a 228.6 millimetres (9.00 in) diagonal screen; incorporates an integrated high-speed Device Cluster Adapter for direct coaxial attachment to the 4701 rather than the loop^[30]
• Model 3 — announced on 3 May 1983 it is functionally identical to the Model 2 and fully compatible with it, but fitted with a larger 304.8 millimetres (12.00 in) diagonal screen; intended for administrative positions where the greater screen area is of value^[30]

Four keyboard types are available:^[30]

• a 50-key Function keyboard with 45 assignable custom keys, suited to teller operation
• a 62-key Alphameric keyboard with a typewriter layout
• a 77-key Expanded Alphameric keyboard adding 15 custom keys to the right of the alphameric section
• a 107-key Administrative keyboard with 43 custom keys, supported on Models 2 and 3 only.

The magnetic stripe unit accepts documents between 0.25 and 0.85 millimetres (0.0098 and 0.0335 in) thick. The reader variant reads plastic cards recorded on Track 2 at 75 bpi to American National Standards Institute (ANSI) standard X4.16-1976; the reader/encoder variant additionally encodes passbooks and other documents at 210 bpi, compatible with 3604 magnetic stripe units.^[30]

The encrypting PIN keypad applies the US Data Encryption Standard (DES) algorithm before transmitting the PIN to the controller, retains its cryptographic key without power for several years, and erases it automatically if physically opened.^[30]

IBM 4710 Receipt/Validation Printer

The IBM 4710 Receipt/Validation Printer, announced on 14 September 1981, is a compact bidirectional wire-matrix printer for the teller work station. It prints on single-, double-, or triple-part cut forms — including receipts, cheques, and validation documents — and can maintain a simultaneous one- or two-part journal roll in a key-locked compartment. Using its 96-character set, the 4710 prints at up to 120 characters per second at 12 characters per inch (48 characters per line), or up to 100 characters per second at 10 characters per inch (40 characters per line). A bold, double-width printing mode is also available for highlighted fields, operating at half normal speed.^[30]

IBM 4720 Forms/Passbook Printer

The IBM 4720 Forms/Passbook Printer, announced on 1 February 1983, is a small desktop wire-matrix printer available in four models for use at both teller and administrative work stations.^[30]

The four models are:^[30]

• Model 1 — prints on cut forms only; directed toward the administrative work station
• Model 2 — prints on cut forms with a simultaneous journal roll; directed toward teller positions where passbook printing is not required
• Model 3 — prints on cut forms and on horizontal-fold or vertical-fold passbooks, without journal; offers more precise print registration on cut forms than Models 1 and 2
• Model 4 — prints on cut forms, passbooks, and journal roll; otherwise identical to the Model 3 in capability and print registration

IBM 4723 Document Processor

Announced by IBM in May 1982,^[34] the IBM 4723 Finance Communication Document Processor is a small desktop reader and inscriber that attached to IBM 3600 or IBM 4700 Banking controllers using the B-Loop connection method.^[35]

It was developed by the IBM Nordic Laboratory in Lidingoe Sweden and manufactured by IBM in Greenock, UK.^[35]

IBM 4730

The IBM 4730 Personal Banking Machine is a self-service financial terminal designed for deployment in bank lobbies, vestibules, supermarkets, and other retail or workplace locations. It attaches to the IBM 4701 Finance Communication Controller and supports SNA/SDLC LU0, BSC-3, and BSC-3 with 3276 emulation communications protocols.^[37] Connected to an System/370 host computer, the 4730 can accept cheque deposits without deposit slips, deliver cash against pay cheques, adjust account balances, and dispense exact change including coins. The coin-dispensing capability was later discontinued as the feature proved costly and saw little customer use.^[6]

Key features include:

• 480-character display on a 9-inch diagonal (23 cm) screen with selection keys
• Numeric keypad with function keys
• Magnetic stripe card reader
• Integrated statement printer
• Currency dispensing in up to five denominations plus four denominations of coin
• Cheque deposits without envelopes via built-in magnetic ink character recognition (MICR) reader
• Exact-amount cheque cashing
• Automatic multiple language support based on the customer's card

The 4730 is offered in twelve models across three tiers:^[37]

• Base models (F01, F02, R01, R02) — Track 2 card reader, statement printer capacity of 1,000 forms. Announced 6 December 1983^[20]
• Enhanced models (F11, F12, R11, R12) — Track 1/2/3 card reader with Track 3 read/write, statement printer capacity increased to 1,900 forms. Announced 27 November 1985^[20]
• Heavy-duty models (F51, F52, R51, R52) — certified to UL 291 for 24-hour unattended service, reinforced enclosures with key-and-combination locks, vandal-resistant gates, and enlarged cheque depository (approximately 600 items). Announced 27 November 1985^[20]

All models are available in single-console or dual-console configurations, with dual units sharing a common currency dispenser and logic module. The modular design supports free-standing or in-counter installation, with removable exterior panels that can be repainted or replaced to match branch décor.^[37]

IBM 4731

The IBM 4731 Personal Banking Machine is a cash-dispensing terminal designed for through-the-wall, vestibule, and off-premises installations such as convenience stores, supermarkets, and railway stations. IBM emphasised the machine's compact physical design, with particular attention to ergonomics, privacy, and visual appearance for public-facing environments.^[38]

Key features included:

• Cash withdrawals, account balance enquiries, and funds transfers
• Support for additional bank-defined transactions
• One currency feed module as standard, expandable to a maximum of four
• SDLC and BSC-3 communications at 1,200 to 9,600 bit/s
• Local attachment to an IBM 4701 or IBM 4702 via SDLC, or remote attachment via modems

The 4731 is offered in two models:

• Model BH1 — included an IBM-supplied hardened enclosure rated to UL 291 safe standards, compliant with U.S. Federal Regulation P for unattended operation
• Model BO1 — omitted the enclosure, providing attachment points for installation into a customer-supplied safe

IBM 4732

The IBM 4732 Personal Banking Machine is a through-the-wall and lobby terminal designed to handle both cash and non-cash banking transactions. Announced on 3 November 1987 with a purchase price of US$19,900 per unit, it was positioned as a direct physical and logical replacement for the IBM 3624 and certain other manufacturers' ATMs, fitting within existing wall openings and attaching to most established ATM networks. General availability was planned for the third quarter of 1988.^[39]

The customer-facing interface features a 9-inch diagonal (23 cm) positive-image CRT display with 480 characters arranged in 12 lines of 40, fitted with a limited-angle privacy filter restricting the viewing angle to 24 degrees either side of centre. Eight display selection keys flank the screen, and the standard consumer keyboard provides 16 keys in a 4 × 4 layout; an optional 32-key extended keyboard is available for institutions already using the same layout on the 3624, 4730, or 4736.^[39]

Key features include:

• Currency and coin dispensing in up to four denominations each
• Statement printing on pre-printed fan-fold forms (up to 5,000 sheets capacity)
• Cheque depository with magnetic ink character recognition (MICR) reader and approximately 600-cheque capacity
• Envelope depository
• DES encryption and decryption
• Multiple language support (up to four languages per machine), selectable by card identifier or customer choice
• Diskette-based journaling on a 3.5-inch 1.44 MB system diskette
• Optional video camera interface
• Dynamic reconfiguration upon component failure

The 4732 is offered in two models:

• Model 001 — standard-capacity document cartridges holding approximately 1,900 documents each
• Model 002 — expanded-capacity cartridges holding approximately 2,800 documents each; physically 120 millimetres (4.7 in) taller than the Model 001

Both models include a hardened enclosure rated to UL 291 for unattended operation, with a five-sided penetration alarm grid and contact pins for connection to an external security alarm system. Two document feed modules and one document reject bin are provided as standard, expandable to four feed modules. The standard-capacity cartridges and reject bins are interchangeable with those of the IBM 4736. Either model can be installed in a through-the-wall or free-standing configuration.^[39]

The 4732 attaches to the IBM 4701 or IBM 4702 via SNA/SDLC, BSC-3, or the 4700 B-Loop protocol. An optional IBM 3624 Emulator feature supports both Version 7 and Version 8 of the 3624 protocol, enabling existing host applications to run with minimal modification — though attachment to an IBM 3600 system is not supported. A separate Alternate Connect feature allows the 4732 to attach to most SNA and bisync ATM networks at speeds up to 9,600 bit/s, including those using the Diebold 911 protocol and equivalents from Burroughs, Fujitsu, NCR, and Omron, enabling the machine to be substituted for a competitor's terminal without significant changes to the host application.^[39]

IBM 4736

The IBM 4736 Personal Banking Machine is a compact self-service cash dispenser designed for bank lobby and vestibule use, as well as indoor off-premises locations such as airports, railway stations, department stores, and supermarkets. It is not designed for exterior installations where it would be exposed to weather.^[40] It can be installed free-standing, built into an interior wall, or set into a teller counter.^[40]

The 4736 was announced on 27 November 1985 with a purchase price of US$16,800 for the Model RH2 and US$14,300 for the Model RS2; general availability was planned for September 1986.^[40]

Key features include:

• Cash dispensing in up to two currency denominations, with electronically locked cartridges each holding approximately 2,050 new notes
• Account balance enquiries, funds transfers, and customisable bank-defined transactions
• 480-character CRT display with adjacent selection keys, fitted with a limited-angle privacy filter restricting the viewing angle to 24 degrees either side of centre
• Numeric keypad with function keys
• Variable-length receipt printer using roll paper, printing up to 48 characters per line at a minimum of 100 characters per second, with a capacity of approximately 2,500 receipts
• Magnetic stripe card reader — Track 1, 2, and 3 (with Track 3 read/write encoding)
• Japanese Universal Credit Card (JUCC) reader
• Local PIN validation within the terminal
• Support for major worldwide currencies and languages
• Dynamic reconfiguration upon component failure

The 4736 is offered in three models, each with two document feed modules as standard:^[40]

• Model RH2 — IBM-supplied hardened safe enclosure rated to UL 291 for unattended operation, with dual-custody access and optional alarm grids
• Model RS2 — IBM-supplied soft enclosure rated to UL 291 for attended operation
• Model R02 (not available in Canada) — shipped as sub-assemblies for installation into a customer-supplied OEM safe

The RH2 and RS2 models were available at announcement; the R02 appeared subsequently.^[40] All models are rear-serviced, with an optional turntable accessory allowing the machine to be rotated 180 degrees for front access. The terminal attaches to the IBM 4701 or IBM 4702 via SNA/SDLC, BSC-3, or the 4700 B-Loop protocol at speeds from 1,200 to 9,600 bit/s. IBM also published a statement of direction indicating its intention to provide a 3624 protocol emulator for the 4736, acknowledging the backward-compatibility concerns that hampered adoption of the 473x series.^[40]

IBM 4737

The IBM 4737 Self-Service Transaction Station is a general-purpose consumer self-service terminal, distinct from the cash-dispensing ATMs in the rest of the 473x family. Rather than handling currency, it is designed to support a broad range of interactive applications beyond traditional banking — examples cited at announcement included car rental bookings, estate agent property listings, hotel reservations, account balance enquiries, standing order arrangements, and investment transactions.^[41]

Key features include:

• Touch-sensitive colour display screen
• Keyboard
• PIN pad
• Processing power of an IBM Personal System/2 Model 30

An application development toolkit was announced alongside the 4737, intended to help software developers produce new packages to run on the terminal. This toolkit approach reflected a shift from the fixed-function design of the earlier 473x ATMs toward a more flexible, software-defined platform aimed at the emerging self-service kiosk market.^[41]