The CONTROL KEYS are:

( NON-ADD )  ( NON-PRINT )  ( REPEAT )
( SUB-TOTAL )
( TOTAL )

The Key  ( NON-ADD )  was missing ...
      ... now replaced by a white plastic cap ...   

T E C H N I C A L   D A T A    of  the  Mechanical  Printing - Calculator
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                                                       BURROUGHS  Class 3
Serial Number:       3-843423

Dimensions:   (ca.)  Width   =  12    " /  30 cm
                     Depth   =  19_1/2" /  50 cm
                     Height  =  11    " /  28 cm

Weight:       (ca.)  40 lbs  /  18 kg

Mechanics:           7*9 Full-Keyboard,

                     Black/RED Nylon Ribbon:
                     7/16" * 16'  /  11 mm * 5 m
                     ( Spool-Diameter = 1_3/4"  /  44 mm )
                     Paper Roll (Standard):
                     2_1/4" * 2_3/4" * 165'  (W * D * L)
                     57 mm  * 65 mm  * 50 m  (B * D * L)

Functions:           Addition, Subtraction ( as 9-Complement Addition )
                     NonAdd, Repeat, Subtotal, Total, NonPrint

Registers:           Input       =  7 Decimals
                     Arithmetic  =  7 Decimals  ( = DISPLAY )
                     Printing    =  8 Characters
Manufacturer:
                     BURROUGHS Adding Machine Co.
                     Detroit, Michigan / USA
                     1920

HOW TO REMOVE THE COVER  &  HOW TO MAKE A »B-KEY«
*************************************************
Observe how the ribbon is spooled:
      LEFT = counter-clockwise / RIGHT = clockwise !!!

(1st) Remove the PAPER MODULE with its 4 screws.
[ ??? Were different modules (e.g. shiftable carriages) available ??? ]
This modul has levers for paper adjustment and line spacing.
(2nd) Remove the BLACK PLATE under it.
(3rd) Remove the 2 SCREWS on the COVER's BACK SIDE.
(4th) Remove the KEY-CAPS of (TOTAL) & (SUBTOTAL) left of the keyboard.
[ The 3 keys (NON-ADD), (NON-PRINT) & (REPEAT) go off with the cover! ]

Try to LIFT THE COVER and notice an INNER HOOK in front.  If it is not
possible to shift the hook with a tip of a knife - A  »B-KEY«  has to
be made - e.g.  OUT OF A  BRASS PIPE  WITH A  NAIL AS HANDLE ...
                                      ( The KINK shows: "Turn left!" )

   W = 2.5 mm     H = 2.0 mm     d = 5.5 mm     D = 6.5 mm

Apply the key, turn it left and lift the cover simultaniously.

HOW TO USE the BURROUGHS CLASS 3
********************************

ADDITION:
---------
Everytime a number is entered and the handle is pulled, the number
is added to the memory ( = DISPLAYED as SubTotal ) and printed,
when the (NON-PRINT) Key is NOT pressed. ( = PAPER SAVING Option )

RESET KEYBOARD:
---------------
If a wrong figure is entered in a column, repeat with the right
figure. To clear the keyboard: Push the (SUB-TOTAL) or (TOTAL) Key.

REPEAT:
-------
To enter the same number more than once, push and lock the
(REPEAT) Key before pulling the handle. To release it, pull the
(REPEAT) Key.

SUBTOTAL:
---------
After printing an empty line ...
The cumulated sum will be printed when the (SUBTOTAL) Key is
pressed & hold before pulling the handle. The memory will hold
the actual sum after releasing both.

TOTAL:
------
After printing an empty line ...
The total sum will be printed when the (TOTAL) Key is pressed
& hold before pulling the handle. The memory will be cleared
after releasing both.

ID-NUMBERS:
-----------
An ID-Number can be entered and printed with the (NON-ADD) Key.
This input is not registered in the arithmetic unit. 

SUBTRACTION:
============
For SUBTRACTION  9-Complement "Addition" has to be used.
(For DETAILS see the  INSTRUCTIONS to the  CLASS 5  CALCULATOR ... )

PRINTOUT - Example             with Comments:
*********************************************

^^^^^^^^^^^^^^^^   To clear memory:
|            * |   Push & hold (TOTAL), Pull handle
|              |   [Printed Red]  Memory is clear!
|              |   
|              |                        < Max.Input = 7 decimals > 
|  12,345.67   |   Enter (1st) number, Pull handle
|  23,456.78   |   Enter (2nd) number, Pull handle
|              |   Pull handle [ = empty line ]
|  35,802.45 S |   Push & hold (SUBTOTAL) to print sum, Pull handle
|              |   [printed red]
|              |
|       4.56   |   Set (REPEAT), Enter number, Pull handle
|       4.56   |   Release (REPEAT), Pull handle
|              |   Pull handle [ = empty line ] 
|  35,811.57 * |   Push & hold (TOTAL) to print total sum, Pull handle
|              |   [printed red]  Memory is clear!
|              |
|        .47 # |   Enter ID #47, Set (NON-ADD), Pull handle [printed red]
|      67.89   |   Enter value,  Pull handle
|        .11 # |   Enter ID #11, Set (NON-ADD), Pull handle [printed red]
|      54.32   |   Enter value,  Pull handle
|              |   Pull handle [ = empty line ]
|     122.21 * |   Push & hold (TOTAL) to print total sum, Pull handle
|              |   [printed red]  Memory is clear!
|              |
|              |   !!!  A T T E N T I O N  !!!
|  76,543.21   |   Enter (1st) 7-Digit-Number, Pull handle
|  65,432.10   |   Enter (2nd) 7-Digit-Number, Pull handle
|              |   Pull handle [ = empty line ]
|  41,975.31 * |   Push & hold (TOTAL) to print total sum, Pull handle 
|              |   8th-Digit LOST  !!!  < Max.Output = 7 decimals >
|              |   [printed red]  Memory is clear!
^^^^^^^^^^^^^^^^
                   Have a look at "Calculating Trickies" ...
R E M A R K :
=========================================================================
     The  YELLOW LABEL  right in the Paper Module reads:

               +-------------------------------------------------+   
               |   O F F I C E   E Q U I P M E N T   C O R P .   |
               |   S A L E S - S U P P L I E S - S E R V I C E   |
               |  At.1898 101-105 S.W.3rd Ave., Portland 4, Ore. |
               +-------------------------------------------------+
impressum:
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© C.HAMANN           http://public.BHT-Berlin.de/hamann          03/05/10