The Sharp QT-8B and its charging dock

The QT-8B compounded the benefit (at the expense of being heavier) by using re-worked versions of LSI ICs that provided the logic in the QT-8D that function identically but require only about 1/2 the power to operate, allowing the QT-8B to become a cordless machine, receiving its power from a Nickel Cadmium rechargeable battery pack contained within the calculator. The battery pack contains six C-size Nickel Cadmium cells connected in series with each other to nominally provide 7.5V DC at a full charge. A fully battery pack will operate the calculator for approximately three hours of continuous run time. THe QT-8B was among the earliest of the truly portable cordless calcualtors that could be taken anywhere that the need for crunching numbers existed, from the job site to the grocery store.

The QT-8B by itself looks virtually identical to the QT-8D, other than the "CORDLESS" badge on the top of the cabinet above the display panel, and the power switch being oriented vertically rather than horizontally as it was positioned on the QT-8D. The QT-8B (not including its AC/Charging dock) was the same physical size as the QT-8D, but is just over 1/2-pound heavier than the QT-8D because of the weight of the Nickel Cadmium battery pack. The removal of the AC power supply from the QT-8D was offset by new circuitry required for managing the charging of the batteries and providing the necessary voltages for the integrated circuits and display. To provide the QT-8B for operation under AC power, as well as to charge the battery pack, a charging dock, designated model QTA-2, was provided with the calculator. The dock contains the AC power supply that generates 12V DC for that provides power to the calculator for operating it on AC power, as well as for charging the batteries. The calculator slides into the charging dock and latches in place, electrically connecting the calculator to the dock. When in the dock, the calculator will operate from AC power, while also slowly charging the batteries. If the calculator is turned off while in the dock the charging rate is increased because the power supply no longer has to also power the calculator.

Sharp announced the QT-8B in Japan in May of 1970, and at nearly the same time, Sanyo introduced their "handheld" (in quotes because it too is a handful) ICC-82D cordless rechargeable calculator in Japan. The ICC-82D appeared on retailer shelves in the US in September of 1970. Unlike the QT-8B, the ICC-82D incorporates the AC power supply circuitry inside the calculator, meaning that it was not necessary to carry a separate charger with the calculator, just a detachable power cord. THe ICC-82D was also a bit smaller and lighter than the QT-8B, being about an inch thinner, and weighing realy a pound and a half less. The weight difference is partly accounted for by the ICC-82D using only four C-Cell Nickel Cadmium rechargeable batteries versus the six used in the QT-8B. The ICC-82D could run for just about three hours continuously on a full charge, indicating that its circuitry is a bit more energy-efficient than that of the QT-8B. Nickel Cadmium batteries are rather dense for their size, with the added two batteries in the QT-8B contributing to its extra weight.

Like the Sharp QT-8B was a follow-on to the QT-8D, the Sanyo ICC-82D was a follow-on to an earlier Sanyo calculator, but in this case, the earlier calculator was also a cordless machine, although it was considerably larger and heavier than the ICC-82D. This calculator was the Sanyo ICC-0081 cordless "Mini Calculator", introduced in Japan in late 1969. Like the ICC-82D, the ICC-0081 had its AC power supply and battery charger built into the calculator. Unlike, the ICC-82D, the ICC-0081 had a compartment inside the machine for stowing the AC power cord as well another compartment that the user could access that held the sealed Nickel Cadmium battery pack. This made it easy for the owner to remove the battery pack if the calculator was not going to be used for a substantial period of time to prevent possible battery leakage from damaging the calculator, as well as making for easy replacement of the battery pack as it aged and would no longer provide sufficient run-time on a charge. The ICC-0081's battery pack contained six C-Cell Nickel Cadmium batteries producing a total of 6.25 Volts DC. With a full charge, this battery pack was good for about 2 1/2 hours of continuous operation. While the ICC-0081 was actually a tiny bit smaller in overall volume than the Sharp QT-8B, and is actually a shade lighter, the machine's form-factor made it a bit much comfortably be held in a single hand, thus disqualifying it from the "handheld" calculator category. Despite that, the ICC-0081 was among the earliest rechargeable battery-powered cordless calculators in existence, and definitely set the stage for the race to develop the truly handheld rechargeable cordless electronic calculators.

Certainly not to be omitted, Canon had announced its thermal ticker-tape printing Canon Pocketronic calculator in Japan in April, 1970, but didn't actually have it on retail shelves in Japan until October, and wasn't available in the US until the early part of 1971 due to delays in getting the production volume of the thermal printing mechanism to the required level.. The Pocketronic used a series of non-standard-sized Nickel Cadmium batteries generating a total of 15.625 Volts DC, packaged inside the calculator to provide cordless operation. The machine required more battery power than the other handheld machines mentioned here due to the printing mechanism, which required more voltage and power to operate the thermal printing element and paper advance solenoid. A substantial portion of the Pocketronic's mass was due to the batteries, causing it to weigh in at pounds 1.8, making the machine rather svelte compared to the Sanyo and Sharp competitors.. The Pocketronic required an external charger module to charge the batteries and operating from AC power. There were two different external chargers available. The standard Model 10A which came with the calculator, took nearly 14 hours to charge a depleted battery pack and would only allow the calculator to be used on AC power if the batteries were charged to a certain level (e.g., if the battery pack was depleted, you'd have to wait at least six hours before being able to use the calculator on AC power). The optional Model 20A "Hi-Speed Charger" was a bit larger and heavier than the standard charger, and would charge a fully-drained battery pack to full capacity in about three hours, as well as allowing the calculator to be used on AC power when the batteries were depleted after being on the charger for only about five minutes. The Pocketronic was also a bit slimmer than the Sharp QT-8B, and about the same length, and weighed in just about a pound lighter than the QT-8B. The Canon Pocketrinic is considered by most historians to be the first cordless handheld electronic calculator, although it did not actually show up on retailer's shelves in Japan until October of 1970, and not until early February of 1971 in the US. THe delay from announcement to retail availability was caused by Canon putting on a contest to name the calculator, which until the contest ended, did not have a name. Along with this, there was about a two month delay in getting the thermal printer production levels and yields to the point where volume production of the calculator could commence. Once the name had been chosen, the documentation and marketing literature could be prepared, and production of the calculator could begin, which didn't happen until the latter part of 1970.

It's truly difficult, like anything "first", to say which company holds the title of first in this cordless "handheld" electronic calculator category. There are simply too many variables, such as whether or not an external charger disqualifies a calculator from being truly "handheld", or if announcement of really counts, because frequently the announcement of a product preceeds its actual retail availability by at least a couple of months. Does "first" mean the the date the calculator was first announced, or when it was first available for sale through a normal retail outlet? It's all very subject to opinion and perception. Rather than say first for any of these calculators, it seems appropriate to say that they all were available through retail outlets during the first quarter of 1971, and were all instant hits with consumerss because of their ability to provide unteathered calculating power that they could hold in one hand and carry around easily. Those characteristics make all of these calculators revolutionary in their own ways. The time that these "handheld" calculators were considered the latest in technology was short, as in mere months, the calculator on a single IC would debut, paving the way for a shirt-pocketable electronic calculator, a development that made these so-called handheld calcualtors look quaint, if not outdated.