Page 2 

Electronic Hand Held Calculators 


Rockwell Calculators- While HP and TI were battling it out, across the Atlantic UNICOM in the United Kingdom was working on pocket handheld calculators. In 1973 Rockwell International (an Aerospace Company who built the Apollo) bought UNICOM and decided to get into the calculator business. The calculator design and marketing was moved to Anaheim, CA called Autonetics where microchips were designed.. Unlike HP or TI, Rockwell assembled their calculators in Mexico, Japan and the UK. Shown below are examples of Rockwell's first generation calculators. They called their calculators "The Answers".  Rockwell would leave the business by 1977-1978 as they saw the market shrink and they would not be able to compete.

Unlike the basic Rockwell Calculators, such as the 10R, 20R and 30R, the following models used larger and easier to read fluorescent displays, larger key pads and rechargeable batteries.

Rockwell 61R (1974) "Advanced Slide Rule" (Intro 1974 price $119.95) Fluorescent display and rechargeable NiCad batteries. Uses AOS calculating logic, First serious entry into scientific calculators. Having no parenthesis and enter exponent functions were a major shortcoming to make this a competitive calculator.
INSIDE the 61RNotice a special fluorescent tube to provide negative sign and error notice.

Pocket Scientific Calculator

Rockwell 74K (1976): Made in Japan.  Called "the 74K", Has the same functions as the Rockwell 63R and later the 64RD, Uses rechargeable batteries. Comes with billfold storage and instruction manual that fits in the billfold opposite the calculator.
BELOW: Phenolic backed keyboard warped separating contacts, causing keys not to operate. Rockwell tends to hide mounting screw with product serial number to prevent DIYer's to open, which would void the warranty.
ABOVE: Battery Modification on 61R. The original AA NICad battery that came with it is "dead". Modified the battery compartment to take replaceable  NiMH AAA cells that have about 3 times the capacity and holds the charge much longer.
BELOW: Battery Modification on 63R. The original AA NICad battery was missing. Install a AA NiMH battery used for cordless phones. A perfect fit but with 3 times the storage and will hold charge much longer.
BELOW: Inside the 74K. Compare that to the older 63R on the RIGHT. Notice that commercial grade phenolic boards are used instead of military grade fiber glass on the 63R.
BELOW: Printed wired board of the 74K. Replaced NiCd cells with newer NiMh cells.
ABOVE: Inside the 74K. BELOW: Inside the 24K. Notice the different rechargeable batteries.
RIGHT: Components inside the 24K --->BELOW: Model 24K DC to DC Converter to operate Fluorescent Display.
Rockwell 63R (1975-76) "Scientific Slide Rule" (1975 price $99.95) Fluorescent display and rechargeable NiCad batteries. Competitive with HP 35/45 and TI SR-50/51 scientific calculators. Uses AOS calculating logic, and features entering exponent, factorial and parenthesis priority calulating.
INSIDE the 63R- Compare this with the 61R made a year earlier. The special fluorescent tube for negative and error notice has been incorporated in the new display. Many discrete parts have been integrated. Rockwell touted the use of military grade fiber glass printed wired boards that year.

Pocket Personal Calculator

Rockwell 24K (1975): Made in Japan and Taiwan  Called "the 24K", Has the same functions as the Rockwell . Similar to the Rockwell 24RD. Uses button type rechargeable batteries. Comes with billfold storage and pen that fits in the billfold opposite the calculator.

SPECIALTY CALCULATOR

Rockwell 51R (1974) "Converter" Fluorescent display and rechargeable NiCad batteries. Basic functions but can convert from metric to English units and back. Can also do double value (meters/second to miles/hour) conversions.
INSIDE the 51R Notice a special fluorescent tube to provide negative sign and error notice.
ABOVE: The original AA NICAD battery block was totally "dead". Modified the battery compartment with removable AAA NiMh cells which have about 3 times the capacity and hold charge much longer.

-----------------------------------------------------------------------------------------------------

<<< BACK TO BEGINNING  PHOTO COLLECTION INDEX

>>> Go to Children's Toys:  CHILDREN'S TOYS

<<< GO BACK A PAGE  HP CALCULATORS