Paul Bruning Resulta-9  
Written by Accutron on 2017-06-10  

Paul Bruning's diminutive Resulta 9 is an advanced type of rotary disc adding machine, similar to the AMCO / Todd Protectograph 'Star' adding machine from 1917. Exposed on the face of the Resulta 9 are nine ratcheting toothed discs which are set with an included stylus. The stylus is placed in the selected column, in a depression adjacent to the number to be entered, and the disc is rotated downward until the stylus stops at the bottom of the column. The bottom register displays the last entered value, while the top register displays the accumulator. New input is immediately applied to the accumulator as it is entered. An input control bar at the front of the machine is depressed to reset the discs and display register, and can be set to instantly reset with a locking lever located on the right side of the machine. When the input control bar is set to immediately reset, the Resulta mechanism becomes completely indifferent as to the order in which digits are entered. For example, the calculation of 123+456+789 can be entered as 3-1-2-6-4-5-9-8-7, or 1-4-7-2-5-8-3-6-9, or any other possible combination.

Unlike the earlier Star adding machine, which relies on the addition of complements to perform subtraction, the Resulta 9 performs direct subtraction with a complementary accumulator, and is capable of subtracting below zero. The Resulta 9 is also much smaller than the Star, but its small size requires the use of a stylus while the Star can be operated with a finger.

Resulta Machine Types

Beginning production in 1927, Paul Bruning manufactured four models of Minverva / Resulta adding machines in both 7- and 9-column variants. Resulta-A is the base model with no subtraction function or input control, while the Resulta-B adds input control. Resulta-AS and -BS include a direct subtraction function. Paul Bruning halted manufacture of all Resulta models in 1943, after their factory was destroyed in the Battle of Berlin. Production of the Resulta-BS resumed in 1950, and the mechanism was incrementally refined in the following years. Export models were introduced around 1955, adding a sliding aperture over the accumulator which allows subtraction results to be viewed directly. Machines from the late 1950s and 1960s replaced the clearing crank with a small lever. The final iterations of the Resulta were the P7 and P9, printing models based on the Resulta-BS Export.

RESULTA-A: No subtraction fuction, no input control.
Type 1 (Minerva / Resulta-"A7" / Resulta-"A9")
Type 2 (Minerva / Resulta-"A7" / Resulta-A"7" / Volksrechner / Resulta-"A9" / Resulta-A"9")

RESULTA-B: No subtraction function, input control.
Type 1 (Minerva-B"7" / Resulta-"B7" / Minerva-B"9" / Resulta-"B9")
Type 2 (Minerva-B"7" / Resulta-"B7" / Resulta-B"7" / Minerva-B"9" / Resulta-"B9" / Resulta-B"9")

RESULTA-AS: Subtraction function, no input control.
Type 1 (Minerva / Resulta-"A7"S / Resulta-"A9"S)
Type 2 (Minerva / Resulta-"A7"S / Resulta-AS"7" / Resulta-"A9"S / Resulta-AS"9")

RESULTA-BS: Subtraction function and input control.
Type 1 (Minerva-B"7"S / Resulta-"B7"S / Resulta-"BS9")
Type 2 (Minerva-B"7"S / Resulta-"B7"S / Resulta-BS"7" / Resulta-"BS9" / Resulta-BS"9")
Type 3 (Resulta-BS"7" / Resulta-BS7 / Resulta-BS"9" / Resulta-BS9)
Type 4 (Resulta-BS7 / Resulta-BS9)
Type 5 (Resulta-BS7 / Resulta-BS9)
Type 6 (Resulta-BS7 / Resulta-7 / Tower / Resulta-BS9 / Resulta-9)
Type 7 (Resulta-7 / Resulta-9)

RESULTA-BS EXPORT: Subtraction function, input control and direct-view subtraction result.
Type 6 (Resulta-BS7 Export / Resulta-7 Export / Resulta-BS9 / Resulta-9)
Type 7 (Resulta-7 Export / Resulta BS"7"Export / Resulta-E7 Export / Resulta-9 / Resulta-E9)
Type 8 (Resulta / ADDICAL)

RESULTA-P: Subtraction function, input control, direct-view subtraction result and printing mechanism.
Type 7 (Resulta P7 / Resulta P9)
Type 8 (Resulta P7 / ADDICAL 7)

Description of Types

Manufacturing years represent the oldest examples currently known. If you have a machine which indicates an earlier date, please contact us.

Type 1 (1927): Riveted housing, wood base, clearing crank, metal crank handle, external clearing lock on subtraction models.
Type 2 (c.1935): Iron base; otherwise like Type 1.
Type 3 (c.1943): Spot welded housing; otherwise like Type 2.
Type 4 (c.1953): Plastic crank handle; otherwise like Type 3.
Type 5 (c.1954): Plastic and aluminum base with rubber feet, ventilation slits in housing, additional left side stylus clip; otherwise like Type 4.
Type 6 (c.1955): Internal clearing lock, plastic cap on subtraction lever, housing fastened to base with spring lock; otherwise like Type 5.
Type 7 (c.1959): Clearing lever instead of clearing crank, metal pin beneath right side stylus clip; otherwise like Type 6. Resulta P7 of this type has 9-column case with columns offset to right side.
Type 8 (c.1963): 7-column mechanism centered in 9-column case, otherwise like Type 7.

Paul Bruning Resulta-9 rotary disc adding machine with original stylus, 955 (September 1955) date code.

Resulta-9, faceplate removed.

This article is part of the [Mechanical Calculators] exhibit.

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