|By 1961, transistors had gained a foothold in business systems. The first minicomputers had started to appear on the market, and the first fully electronic desktop calculators, the Sumlock ANITA Mk VII and Mk VIII, were introduced. Transistors were very expensive in 1961, so Sumlock opted to use miniature thyratrons as the switching elements in the ANITA. The ANITA was capable of performing addition, subtraction, multiplication and division, and used a Comptometer-style input system and Nixie tube readout. By the mid-1960s, Japan had introduced transistorized desktop calculators, and would soon be producing machines built on discrete bipolar and MOS logic.|
In 1964, a small company named Mathatronics completed development of the Mathatron, the first electronic programmable desktop calculator. Introduced more than a year before the more well-known Olivetti Programma 101, the Mathatron used full algebraic entry, complete with parentheses. The Mathatron featured an unusual 'ticker tape' style printer, whose output doubled as a single-line display.
Texas Instruments foreshadowed the rapidly approaching handheld calculator market in 1967, with the announcement of the experimental 'Cal-Tech' calculator. Like the aforementioned Mathatron, the Cal-Tech made use of ticker tape style printer which doubled as a display. Unlike the Mathatron printer, which utilized a conventional impact mechanism, the Cal-Tech's printer employed TI's new thermal printing technology.
In 1968, Hewlett-Packard introduced the 9100A, the world's first desktop programmable scientific calculator. The 9100A featured discrete diode and transistor logic, RPN entry, and used the famed CORDIC algorithm to compute transcendental functions. The success of the 9100A lead directly to the development of HP's powerful 9800-series desktop instrumentation control calculators, as well as their personal calculator product line.
In 1970, MOS LSI technology became available for calculator products. Several manufacturers introduced large LSI-based handheld calculators, distinctively larger than a pocket calculator but handheld nonetheless. Sharp introduced the EL-8, based on a four-chip Rockwell chipset and Iseden Itron VFDs. Canon introduced the Pocketronic, a commercialization of the original TI Cal-Tech design, with a three-chip TI chipset and ticker tape printer/display. In 1971, Mostek introduced the MK6010 single-chip calculator, and Bowmar entered the market with the 901B 'Brain', a truly pocket-sized handheld calculator with a TI single-chip calculator LSI and compact Bowmar Opto-Stic LED display. Over the next two years, dozens of companies leapt into a brutal fight for dominance in an explosive new handheld calculator market, armed with LSI chipsets and single-chip calculators manufactured primarily by TI, AMI, Mostek, Rockwell and various Japanese manufacturers.
In 1972, TI began in-house calculator production with the TI-2500 Datamath four-function handheld calculator. The Datamath used a TMS0110 single-chip calculator, similar to chips and small chipsets they had previously sold to other calculator vendors. Just a few months later, HP introduced the HP-35, the world's first handheld scientific calculator. The HP-35 originated in a demand made by Bill Hewlett several years earlier, for a pocket-sized version of the 9100A. The HP-35 used a two-chip PMOS CPU, designed by HP and fabricated by Mostek and AMI. The introduction of the HP-35 brought about the end of the slide rule era. College curricula previously centered around the use of traditional logarithmic slide rules were quickly rewritten to make use of the new "electronic slide rules", although some institutions maintained a ban on calculators into the 1980s.
The TI-2500, HP-35 and their many successors captured almost all of the US calculator industry. Canon, Casio and Sharp secured most the Japanese industry, and the calculator wars came to an end. These survivors would set the tone of the US calculator market for the next 40 years: TI would dominate the lower end student and general consumer customer base (with the Japanese manufacturers constantly nipping at their heels), while HP would enjoy a mostly uncontested monopoly of the professional scientific, engineering and financial calculator market sectors.
Programmable calculators would not be effectively supplanted by computers until the 1990s, when powerful mathematical software packages such as Matlab and Excel started to gain dominance in professional engineering and financial applications. Calculators were still the preferred device for 'back of the napkin' calculations, until the smartphone revolution of the mid-2000s. Device convergence has now relegated the calculator to very specific markets, primarily high school and college courses and exams, where only certain devices are permitted. In this context, the restricted functionality of a calculator is ironically considered a feature.
|Hewlett-Packard 80 & 45
Devices included in this entry:
Hewlett-Packard 80 Financial Calculator
Hewlett-Packard 45 Advanced Scientific Calculator (pictured in thumbnail)
In 1972, Hewlett-Packard introduced the HP-35 scientific calculator, fundamentally altering the way humans would perform higher mathematics for the first time in 450 years. Commercial digital computers and calculators had been available for over two decades, but systems were large, expensive and limited in availability. Minicomputers were in their heyday, but computer and scientific calculator access was still limited primarily to governments, businesses and educational institutions. The HP-35 single-handedly democratized computation. It was, in every meaningful sense, the world's first personal computer and the world's first handheld computer.
Despite its revolutionary capabilities, the HP-35 did not fully implement a number of features that would soon become common on HP scientific calculators. The HP-35 served as a sort of large-scale production prototype, establishing the architecture and construction methods that would be used in subsequent calculators, as well as acclimating HP to the vagaries of manufacturing and selling a high-volume consumer product for the first time.
Exactly one year after the launch of the HP-35, Hewlett-Packard introduced the HP-80, a financial calculator built on the same architecture and mechanical specification as the HP-35. While the HP-35 was equipped with three ROMs, the HP-80's microprogrammed space was expanded to seven ROMs, all contained within a single custom hybrid IC package. The HP-80 also introduced the shift key, a revolutionary improvement in key-per-function calculation, which doubled (approximately) the the number of functions accessible to the user for any given key count. Since the HP-80, shift and alpha keys have become ubiquitous on scientific and financial calculators from all manufacturers.
Three months after the HP-80, Hewlett-Packard introduced the HP-45, their second scientific calculator. The HP-45 was an upgraded HP-35 with a greatly expanded ROM and ten 56-bit storage registers. As the HP-45 was HP's first mature scientific calculator, it introduced a range of important new functions. The HP-45 was the first HP handheld calculator with storage registers, the first with a formatted display, the first with a LAST X register and the first handheld scientific calculator with a shift key. While the earlier HP-80 financial calculator was also equipped with a shift key, it was not fully implemented, as most keys on the HP-80 do not have a shifted function. Other than the aforementioned improvements, the hardware of the HP-45 is nearly identical to that of the HP-35 and HP-80, sharing a common architecture, display technology and case construction.
Perhaps the most commonly noted feature of the HP-45 is its undocumented timer mode. Pressing [RCL], then pressing [CHS]   simultaneously will activate a timer function, displaying hours, minutes, seconds and milliseconds. After entering timer mode, [CHS] starts and stops the timer. Pressing  through  while the timer is running stores the current timer value in the corresponding register, and recalls the time from the same register if the timer is stopped. Pressing [.] exits timer mode while keeping the currently displayed timer value in the bottom level of the stack, and pressing [ENTER] exits timer mode and clears the timer value. Although the HP-45 has the completely functional timer microcode, there is no external crystal to provide accuracy. The timer function is fully implemented and documented in the key-programmable HP-55.
The HP-45 also marks the last time HP would manufacture a calculator with a black case for over 30 years. Upon first seeing the HP-45, Bill Hewlett commented that black was a "very unimaginative color," and asked if all future models were going to be black as well. This singular comment resulted in all subsequent HP calculators being made in a wide range of aesthetically questionable, business-friendly colors, such as dark green, dark brown and tan. HP would not manufacture another black calculator until long after the dismantlement of their original calculator division.
HP-80 Owner's Handbook (PDF)
HP-80 Quick Reference Guide (PDF)
HP-80 Application Notes 1-10 (PDF)
HP-80 Real Estate Applications (PDF)
HP-80 Brochure: "The Hewlett-Packard HP-80 Computer Calculator" (PDF)
HP-45 Owner's Handbook (PDF)
HP-45 Quick Reference Guide (PDF)
HP-45 Applications Book (PDF)
HP-45 Brochure: "Not only is it up to 50 times faster than this..." (PDF)
HP-45 Brochure: "The Hewlett-Packard HP-45 Advanced Scientific Pocket Calculator" (PDF)
HP-45 Brochure: "compare!" (PDF)
HP-45 Accessories Catalog (PDF)
US Patent 4001569: General Purpose Calculator Having Selective Data Storage, Data Conversion and Time-Keeping Capabilities (PDF)
Devices included in this entry:
Hewlett-Packard 9820A programmable calculator (pictured in thumbnail)
Hewlett-Packard 11220A Peripheral Control I ROM cartridge
Hewlett-Packard 11221A Mathematics ROM cartridge
Hewlett-Packard 11223A Cassette Memory / Special Programs ROM cartridge
Hewlett-Packard 9820A to 9866A Printer interface
Introduced in 1972, the 9820A is Hewlett-Packard's first algebraic calculator. After the success of the 9100A desktop calculator, HP sought to migrate to a more scalable architecture with their follow-up products, and chose to implement a serialized version of their HP 2100 series minicomputer architecture with added BCD functionality. This approach resulted in the 9810A, introduced in 1971. From a user standpoint, the 9810A was much like the 9100A: a stack-based RPN machine, with key-per-function input and a three line display. Internally, the 9810A was completely different. Instead of using discrete diode and transistor logic with core memory and a CRT display, The 9810A was built from MSI TTL and semiconductor RAM, and had a numeric LED display. The 9810A also introduced the concept of interchangeable ROMs to HP's emerging line of desktop calculators. While the 9100A was an all-in-one machine hardwired to execute trigonometric functions, the 9810A had three ROM cartridge slots above the display, which allowed a user to configure the machine to meet their specific requirements.
After the introduction of the 9810A, HP announced the 9820A and 9830A in the December 1972 issue of HP Journal. The 9820A and 9830A were to become the standard bearers for two new technologies which had recently been developed at HP: NMOS ROM fabrication and alphanumeric dot matrix LED displays. The combination of cheap ROMs and an alphanumeric readout allowed for the implementation of high level language capabilities on both the 9820A and 9830A.
The 9820A is explicitly an upgraded 9810A, with an alphanumeric readout, a larger internal ROM and more RAM. Instead of being a simple RPN machine, the 9820A is programmed in a proprietary high level language. This language would later evolve into HPL on the successor 9825A system. The 9830A is even further removed from the original 9100A concept, with a QWERTY keyboard, 32-line alphanumeric display and BASIC programming.
With the introduction of both the 9830A and HP-35 in 1972, HP's desktop products and calculator products began to diverge. The 9830A was definitively a general purpose computer, and the HP-35 redefined key-per-function scientific calculation as the domain of relatively low-performance handheld devices. To this day, the 9820A stands as the most powerful key-per-function desktop calculator ever built by HP.
The 9820A pictured here was used internally at HP Loveland, and began its life as a 9810A in early 1972. Nearly a year later, it was converted into a 9820A by installing an upgrade kit which replaced the memory components, keyboard and display module. IC date codes on the original 9810A components range from late 1971 to early 1972, while the date codes on the 9820A upgrade components are from late 1972. As this machine was an internal use system, it lacks a traditional serial number placard, and has a nonstandard number placard and a 'NOT CAPITAL ASSET' sticker below the ROM function keys.
9820A Operating & Programming (PDF)
9810A / 9820A Calculator Service Manual (PDF)
9820A Brochure: "Meet the Conversational Calculator" (PDF)
9820A Calculator - Technical Data December 1972 (PDF)
Series 9800 Pricing Information (PDF)
|Hewlett-Packard 9825A & 9825B
Devices included in this entry:
Hewlett-Packard 9825A programmable calculator (pictured in thumbnail)
Hewlett-Packard 9825B programmable calculator
Hewlett-Packard 98034A HP-IB Interface
Hewlett-Packard 98036A RS-232C Interface
Hewlett-Packard 98210A String - Advanced Programming ROM
Hewlett-Packard 98216A 9872A Plotter - General I/O - Extended I/O ROM
Hewlett-Packard 98224A Systems Programming ROM
Despite its relative obscurity, the Hewlett-Packard 9825A programmable calculator is the world's first 16-bit microcomputer, and one of the single greatest leaps in computer technology since the invention of the transistor. Introduced in January 1976, more than a year before the first consumer 8-bit personal computers, the 9825A is built around HP's proprietary 16-bit NMOS hybrid microprocessor, providing the 9825A with fast minicomputer-class processing power. The 9825A has an integrated magnetic cassette drive and thermal printer, as well as a wide range of expansion and interfacing options.
The 9825's three-chip hybrid microprocessor consists of the Binary Processor Chip (BPC), Extended Math Chip (EMC) and Input-Output Controller (IOC). The BPC is a single-chip implementation of the core ISA used in the early HP 2100 series minicomputers. The EMC is a floating point processor which executes BCD arithmetic instructions derived from the earlier 9810/20/30 calculators, and the IOC implements I/O, DMA and other related instructions. Together, the three chips are the approximate equivalent of a fully loaded HP 2116 minicomputer CPU with added mathematical functionality.
The 9825A runs HPL (High Performance Language), a proprietary high-level programming language with similarities to APL and BASIC. HPL is an expanded implementation of the programming language used on the 9820A, optimized for calculation and instrument control, and was a personal favorite of HP Labs founder Barney Oliver.
Although it was originally intended as a replacement for the proto-HPL 9820A calculator, the 9825A had evolved to incorporate features from the more computer-like 9830A BASIC system, including the 32-character alphanumeric display, tape drive and QWERTY keyboard. In 1978, HP introduced the 9831A, a renumbered 9825A which omits the HPL interpreter in favor of 9830A BASIC.
In 1980, HP introduced the 9825B, with a revised hybrid microprocessor, full travel keyboard, 23.2K RAM standard, and integrated String, Advanced Programming, Plotter, General I/O and Extended I/O ROMs.While the 9825A retains the multi-level indirect addressing capability of the early HP 2100 series minicomputers, the revised microprocessor in the 9825B abandons multi-level indirect addressing in favor of being able to address up to 64K of memory.
The 9825 had several competitors at the time of its introduction, namely the IBM 5100, Wang PCS II, Tektronix 4051 and Olivetti P6060. The 9825 was faster, lighter and more affordable than any of these competing machines. In particular, the 9825A is nearly 15 times faster than the IBM 5100, released only four months earlier. Although both machines are built upon a 16-bit architecture and are capable of addressing up to 64KB of memory, the IBM 5100 utilizes the board-level PALM (Put All Logic in Microcode) processor. PALM is built from 13 discrete bipolar gate arrays, operating at 1.9MHz. In sharp contrast, the CPU of the 9825A is a three-chip (plus four bidirectional interface buffers) NMOS design mounted on a single leadless carrier, operating at 10MHz. Beyond its raw power, the 9825A also has a superior feature set and range of interfacing options.
Despite its relatively wide adoption, groundbreaking technology and nearly supernatural capabilities, the 9825A has been mostly ignored in the mainstream pantheon of computer history. While the 9825A was eminently affordable to corporate and government entities, it was well outside the price range of consumer hardware which might garner attention from amateur users' groups and mass media. Although the IBM 5100 was in a similar position to the 9825, it has been retroactively deified by computer historians due to its status of being IBM's first 'personal' computer, as well as it having the rather dubious distinction of playing a key role in the John Titor time traveler internet folk tale.
HP also made the marketing mistake of intermittently referring to the 9825A as a calculator or instrument controller, emphasizing its HPL programming language and BCD arithmetic rather than its general purpose capabilities. The original patent for the 9825A refers to it as a calculator, and the codename for the 9825A is 'Keeper', a reference to the key-per-function calculator keyboard originally specified. Feature creep during development eventually outgrew the capacity of a key-per-function interface, and the 9825A was redesigned around a QWERTY keyboard. The vestiges of the original key-per-function keyboard can be seen in the 9825A, which uses a chiclet-style keyboard with metal dome switches, similar to HP's handheld calculators. This keyboard was highly reviled by touch typists, and was replaced with a full-travel Cherry switch keyboard in the 9825B.
9825A-B Operating & Programming Reference (PDF)
9825A System Test Booklet (PDF)
9825A General IO Programming (PDF)
9825A Extended IO Programming (PDF)
HP 9825A-B Service Manual (PDF)
9825A-B CE Handbook (PDF)
98032A-98033A-98034A Interface Cards - Technical Data (PDF)
Calculator Users' Club - Introductory Package (PDF)
US Patent 4075679: Programmable Calculator (PDF)
The How They Do Dat Manual (PDF)
Reference Manual for the CPD N-MOS II Procesor (PDF)
Nanoprocessor User's Guide (PDF)
In 1976, Hewlett-Packard simultaneously introduced the HP-67 and HP-97, second-generation updates to HP's first programmable handheld calculator, the HP-65. Like the HP-65, the HP-67 is a card-programmable handheld, but the HP-97 has a portable desktop form factor, which adds a thermal printer and other improvements. Despite its form factor, the HP-97 has a large rechargeable NiCd battery, and is light and compact, making it an effective two-handed portable device. HP's 'Topcat' series, which includes the HP-97 and the non-programmable HP-91 and HP-92, are based on HP's second generation 'Woodstock' manufacturing techniques, but retain the 15-digit display of HP's first generation calculators. Woodstock series handheld calculators are equipped with a 12-digit display, on which the mantissa must share digits with the exponent. HP would not produce another calculator with a display possessing more than 12 digits until the introduction of the HP-18C in 1986. The HP-67 and HP-97 represented a total convergence of calculator functionality, immediately supplanting all of HP's previous small key-per-function machines.
The HP-97 is a unique among HP's 'personal calculator' product line (which excludes the HP-9100 and the large 9800-series industrial calculators and computers manufactured by HP's Loveland Calculator Division.) It is the only programmable personal desktop calculator ever built by HP, and the only HP personal calculator with both a card reader and a printer in a single mechanical package. The HP-97 has the highest key count of any HP personal calculator not equipped with an alphabetical keyboard - 14 more keys than the HP-91 and HP-92. Topcat series machines are also the only HP desktop calculators to be equipped with a battery. The HP-67 and HP-97 also introduced several critical programming improvements over the HP-65, including indirect addressing, fully merged key codes and the ability to read and write data on magnetic cards. The addition of indirect addressing is of particular importance as it, combined with the conditional branching capability inherited from the HP-65, elevates the HP-67 and HP-97 to the status of being true Turing-complete computers.
Although it is often crudely referred to as a 'desktop HP-67 with a printer', the HP-97 has a number of notable differences which make it a more usable and resilient calculator. Unlike HP handheld calculators, which all have metal dome switch pads with hinged plastic key caps, the HP-97 has linear travel coil spring keys. While the distinctive HP tactile feedback is absent, the linear keys are optimized for rapid data entry, and are not susceptible to the types of failures endemic to metal dome switches. The HP-97 also has 56 keys (scanned in a 4x14 array) and a single shift key, as opposed to the HP-67's 35 keys and three shift keys. This configuration means that more functions are unshifted on the HP-97, resulting in a lower average number of keystrokes per operation. The HP-97 is also equipped with a Printer Interface / Keyboard (PIK) IC, which not only drives the integrated thermal printer, but also includes a keyboard buffer which stores up to seven key codes, and debounces the keyboard by delaying key codes approximately 4.5ms.
Another design advantage, of particular interest to calculator collectors, is that the HP-97 is built to be easily repaired. It requires neither the removal of stickers or adhesive rubber feet to gain access to the interior of the unit, nor the application of razor blades, power drills, hair dryers or ultrasonic cleaners to perform basic servicing procedures.
HP later introduced the HP-97S I/O Calculator, an otherwise standard HP-97 with a rerouted logic PCA, designed to more easily accommodate a permanently attached BCD interface pod. After the introduction of the HP-97S, the HP-97 was built with the new PCA layout as well, and simply omitted the interface pod. These later units can be easily identified by the presence of unpopulated solder pads for a 16-pin DIP.
HP-97 Owner's Handbook and Programming Guide (PDF)
HP-97 Service Manual (PDF)
HP-67 & HP-97 Brochure (PDF)
HP-67 & HP-97 Comprehensive Software Support (PDF)
|Hewlett-Packard 48 Series
Devices included in this entry:
Hewlett-Packard 48G graphing calculator (pictured in thumbnail)
Hewlett-Packard 48GX expandable graphing calculator
Hewlett-Packard 49G graphing calculator
The Hewlett-Packard 48 is the final evolution of the RPL scientific calculator. The HP-48 features a 131x64 LCD display, unlimited stack (within memory constraints), advanced graphing capabilities, a fully developed file management system, wired and infrared communication with multiple protocol options, and extensive RAM and software expansion options in certain models. All models in this series are built upon HP's Saturn CPU, first introduced in the HP-71B handheld computer and later used in the HP-28C and 28S scientific calculators.
The first model, the HP-48SX, was introduced in 1990, and the non-expandable HP-48S arrived a year later. Both the 48S and 48SX have 32K of RAM, but the 48SX is also equipped with two expansion card slots, which accept both battery-backed continuous RAM cards and software ROMs. In 1993, HP introduced the 48G and 48GX, upgraded models with double the processor speed and ROM size. While the 48G retains the 32K RAM specification from the 48S/SX, the 48GX is equipped with 128K of RAM. In 1998, HP introduced the 48G+, essentially a 48G with 128K of RAM (alternately, a 48GX with no expansion slots.)
In 1999, HP made their first departure from traditional calculator development. HP formed the Australian Calculator Operation (ACO), which primarily consisted of programmers from the preexisting HP-48 community. The resulting device was essentially a bastardized HP-48, with improved software, built-in flash memory, a deeply flawed keyboard, and a case design targeted at iMac-addled high school students. Despite its sharp cosmetic departure, the internals of the HP-49 are extremely similar to the HP-48G/GX. The HP-49 was the final calculator product introduced by HP, prior to its dismantlement under the disastrous reign of CEO Carly Fiorina. After the HP-49G, HP's calculator production was offloaded to Kinpo Electronics, who continued manufacturing HP-48 descendants which ran a Saturn virtual machine on ARM hardware. The final Kinpo/ARM descendant of the HP-48, the HP-50G, was discontinued in 2015, killing off the last vestiges of HP's original calculator division.
HP-48G Series Quick Start Guide (PDF)
HP 48G Series User's Guide (PDF)
HP 48G Series Advanced User's Reference Manual (PDF)
HP 49G Advanced Users Guide (PDF)
HP 49G Advanced Topics (PDF)