Differences
This shows you the differences between two versions of the page.
|
burroughs_class_5 [2019/05/17 20:34] clodoveu |
burroughs_class_5 [2019/05/17 22:32] (current) clodoveu |
||
|---|---|---|---|
| Line 5: | Line 5: | ||
| * [[calc|Back to Mechanical Calculators]] | * [[calc|Back to Mechanical Calculators]] | ||
| - | This machine was manufactured by Burroughs in the United States, at a factory in Detroit, Michigan, in 1926 or 1927 (see [[http://www.burroughsinfo.com/when-was-my-machine-made.html|here]]). I bought it at an online auction site, in May 2019, from just two posted images. I took the chance of buying without being able to see much of the machine's condition, but this one is older, rarer in Brazil, and has a simpler mechanism, based on the Comptometer. Online sources say that Burroughs was sued for nearly copying the Comptometer's working mechanism in other machines, and then came out with the Class 5 with a few innovations, including a more compact design, aiming at desktop use. Earlier bulky Burroughs adding machines were mounted on pedestals and placed at the center of offices, to be shared among many operators. | + | This machine was manufactured by Burroughs in the United States, in Detroit, Michigan, in 1926 (see [[http://www.burroughsinfo.com/when-was-my-machine-made.html|here]]). I bought it at an online auction site, in May 2019, from just two posted images. I took the chance of buying it without being able to see much of the machine's condition, but this one is older, rarer in Brazil, and has a simpler mechanism, based on the Comptometer. |
| - | My unit has seven missing keys, and one white "3" key too many. This was probably a replacement taken from another machine. It was locked and unresponsive, the painted aluminum (?) case sprinkled with paint drops, and all rubber feet crumbling. | + | Online sources say that Burroughs was sued for nearly copying the Comptometer's working mechanism in other machines, and then came out with the Class 5 with a few innovations, including a more compact design, aiming at desktop use. Earlier bulky Burroughs adding machines were mounted on pedestals and placed at the center of offices, to be shared among many operators. |
| - | Online photos of museum units and other well-preserved Class 5s | + | My unit has seven missing keys, and one white "3" key too many. This was probably a replacement taken from another machine. It was locked and unresponsive, the painted aluminum alloy (?) case sprinkled with white paint specks, and all rubber feet crumbling away. The decimal point indicators are also missing. Two of the display's numbered wheels are cracked, one badly and slipping from its position. Those must be glued back in position to work. |
| - | My machine has octogonal keytops for the shift functions, and a knurled lever for the stop/sub function. This lever was replaced with a regular button in later models, and the TK-style octogonal keytops also evolved into rectangular ones. | + | Online photos of museum units and other well-preserved Class 5s show, right to left, two columns of white keys, three blacks, three whites and one black. This points to adding money figures, up to 9,999,999.99. My unit has, right to left, three black columns, three whites, and three blacks. This is probably due to the Brazilian currency prior to 1942, called "réis" (plural of "real"). A single real back then was basically worthless, so money units were called "mil-réis", for thousand reais, and denoted like 1.000$000. Three groups of three columns then make more sense than having two columns for cents, which we did not have back then. The smallest denomination was a 20 réis coin, dubbed the "vintém". The 100 réis coin was called a "tostão", and the highest denomination was worth 1.000$000, or a thousand mil-réis. A million réis was called a "conto de réis". |
| - | My machine also lacks the secondary control lever, to the right of the main control (mult-add-div) lever. This is strange, since the NEA has this lever, and its bottom prints symbols to indicate its function to the operator. Most other pictures of ESA-0 machines I found online also have the secondary lever. So far, I could not find an explanation for this; there is no indication that the lever was removed or broken, though. | + | As essentially a Comptometer, this machine does not actually add fully input numbers to an accumulator on command. The lever to the right is only used for clearing. As keys are pressed and released in each column, the mechanism immediately advances the corresponding digit by the required number of positions, and then carry flows to the digit to the left. The operator never actually sees the number being added anywhere: not in the display, nor as a set of down-pressed keys. The effect of each typed-in digit is immediate, so recognizing and correcting mistakes must have been painful. On the other hand, digits can be input simultaneously, by pressing keys in different columns at the same time -- weird. Also, the effect of pressing, say, 2 and then 5 in a column is the same as pressing a 7 in the same column, but 2 + 5 require less arm and wrist movement. As a result, keys from the bottom rows show much more wear than keys in the top rows. Later machines based on the same principle have only 5 rows of keys, requiring double keypresses to input larger digits. |
| - | Putting it back to work was a demanding process, since initially the motor ran continuously, and all other mechanisms were locked, including the keyboard and main rotor. It took some analysis, observation, kerosene jets and lubrication to unlock the typical parts of the FACITs that cause the most important locks. During two careful days, I made it a new power cable, then I managed to stop the ever-running motor, make the clearing mechanisms work, unlock the main rotor, release the keyboard lock, activate the adding mechanism, and finally get it to do multiplications and divisions. It now works perfectly. | + | It is interesting to notice that adding columns of numbers can be done column-wise, giving the same result. Say you need to add 123 + 456 + 789. You can type in 3 - 6 - 9 on the rightmost column, then 2 - 5 - 8 on the second, and 1 - 4 - 7 on the third, much like adding manually. |
| - | I replaced the acetate windows, cutting from a transparent sheet that is used in packing kiwi fruits for sale in Brazil -- go figure. I have also replaced the rubber rollers at the back with nylon cylinders. At 12 kilos, this was the first FACIT machine to have rollers to help moving it around an office desk. Next step: 3D print the missing keytops. | + | Subtracting in the Class 5 is, as in the Comptometer, also troublesome. The operator is required to enter a tens-complement number, using preceding 9s and typing the number to be subtracted by looking at the small numbers on the keycaps. The preceding 9s are actually zeroes if you look at the small numbers in the keycaps. Oh, and the subtrahend must be reduced by one so the tens-complement works correctly. Whew. More on Burroughs Class 5 operation [[http://public.beuth-hochschule.de/hamann/burroughs/burro5/index.html|here]]. |
| - | Multiplication in the ESA-0 is straightforward: the operator types in the multiplicator, and presses the X button. This places the multiplicator in a "mechanical memory" of sorts, the input register is cleared, and the displays remains zeroed. Then the operator inputs the multiplicand, and presses the = key. The result comes out automatically, with all rotations and shifts performed automatically. It is worth mentioning that the mechanical algorithm implemented in this machine can optimize the number of rotor turns, deciding whether to go forward or backwards so that the number of turns is minimized. | + | My plans: make it work smoothly, which does not seem to be a difficult proposition, then repaint everything, including the numbers on the keytops. I'll also try to produce a stylish Burroughs logo from online photos -- mine only has a small fragment of the logo left. Missing keytops can be 3D-printed, and the rubber feet should be easy to replace. I'll also look into designing the longer back feet (possibly an optional accessory) as in some online pictures, and have them 3D printed as well. |
| - | The operator can help minimizing the machine's effort. As a rule, enter first the smaller number. If the numbers have the same number of digits, there can be a more efficient multiplication order. For instance, if the operator enters 333 x 999 =, the machine stores 333, then spins the rotor with 999 in the input register three times, for each of the three decimal positions, so nine turns are required. If the operator enters 999 x 333 =, then 999 is stored, and with 333 in the main rotor, the machine performs one negative turn (-1 x 333), then shifts left three times, then does one positive turn (+1000 x 333), and completes the task with only three spins. | ||
| - | |||
| - | Division is also fully automatic: after the dividend is input and added to the left of the accumulator, the input register is cleared automatically and the divisor can be keyed in and also shifted to the left. Then the division key starts up a mechanical algorithm by which subtractions and carriage moves to the right go on automatically until the remainder is zero or the precision limit is reached. | ||
| **Have a mechanical calculator stored somewhere, and want to get rid of it? Send it to me!** | **Have a mechanical calculator stored somewhere, and want to get rid of it? Send it to me!** | ||
| - | **1951 FACIT ESA-0 s/n 327930** | + | **1926 Burroughs Class 5 s/n 5-1065827** |
| - | Front view, notice there is no secondary control lever to the right of the main lever | + | As purchased |
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_6.jpg?500 | Front view}} | + | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/Burroughs/Burroughs_1.jpg?500 | As purchased}} |
| - | Left side, cover off | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_1.jpg?500 | Left side}} | ||
| - | Right side, cover off | + | **More about this machine** |
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_2.jpg?500 | Right side}} | + | [[http://www.johnwolff.id.au/calculators/Burroughs/Burroughs.htm | John Wolff shows a wider Class 5, with 13 columns instead of 9, including a column for Sterling currency units]] |
| - | + | ||
| - | Motor, by Electrolux, another Swedish company that decades later acquired FACIT | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_3.jpg?500 | Motor}} | + | |
| - | + | ||
| - | Electrical connections in the motor shaft | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_4.jpg?500 | Electrical connections}} | + | |
| - | + | ||
| - | Front view, still missing three keytops | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_5.jpg?500 | Still missing three keytops}} | + | |
| - | + | ||
| - | Power label at the back. I adapted a Brazilian 20A connector to fit the thick prongs used back then | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_7.jpg?500 | Power label in the back}} | + | |
| - | + | ||
| - | Bottom panel, after treating some rust and replacing the rollers with nylon cylinders | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_8.jpg?500 | Bottom panel}} | + | |
| - | + | ||
| - | As purchased | + | |
| - | + | ||
| - | {{ http://www.dcc.ufmg.br/~clodoveu/files/Images/FACIT-ESA-0/FACIT_ESA-0_as_purchased.jpg?500 | As purchased}} | + | |
| - | + | ||
| - | **More about this machine** | + | |
| - | [[http://www.johnwolff.id.au/calculators/Facit/Facit.htm | The evolution of FACIT calculators]] | + | [[https://www.youtube.com/watch?v=MpCXcOcAsHk | Video: a demonstration of the Class 5 in action]] |
| - | [[https://www.youtube.com/watch?v=3Wq6HaHFOHM | Video: a demonstration of the FACIT ESA-0 features and use modes]] | + | [[http://public.beuth-hochschule.de/hamann/burroughs/burro5/index.html | An operations description, including an explanation on subtraction modes and their special cases]] |
| - | [[http://www.rechenmaschinen-illustrated.com/Manuals/Facit_CA1-13-Anleitung.pdf | Manual of the FACIT CA1-13 (in German), similar to the ESA-0 except for the cover, and the separation of the SUB/STOP lever functions into two keys. For some reason, FACIT inverted the numbering of the input and accumulator registers, but not the position of the keys]] | + | [[http://collection.sciencemuseum.org.uk/objects/co59681/burroughs-class-5-hand-operated-mechanical-adding-calculating-machine-full-keyboard-adding | A beautifully preserved unit at the UK's Science Museum]] |
| - | [[http://public.beuth-hochschule.de/hamann/facit/f-ca1/index.html | Another description of the CA1-13, in English, mostly applicable to the ESA-0]] | + | [[https://arildamland.artstation.com/projects/k4lBOl | A time-lapse video of an artist recreating the shape of a Class 5 using only a photo and a 3D design software package]] |
| + | [[https://archive.org/details/burr_instr/page/n9 | Instructions for Operating the Burroughs Calculator. 36 page booklet]] | ||
