Punch card sorter
The punch card sorter (English Sorter ) was a tool of the electromechanical data processing . With it, punch cards could be sorted (put in a certain order) or certain punch cards sorted out .
Stand-alone device
The sorter was not a peripheral device of a computer, but a stand-alone device. He was not 'programmed' but via manual switch to execute functions set . Unlike a punched card mixer or a tabulating machine , the punched card sorter could only process one specific column per pass.
With the help of the sorter, punch cards could be brought into the order required for mixing or processing. For example, the punch cards created by a bank were generated separately according to type of receipt (such as deposits, withdrawals, transfers, checks) and delivered unsorted in this order as a stack. The punch cards had to be sorted by account number for booking processing.
history
Hand sorter
The mechanical punch card sorter goes back directly to the founder of machine data processing, Herman Hollerith . His machines at the end of the 19th century already had sorting compartments. The punched card was inserted into the reading station by hand, a flap on the sorting compartment indicated to the "operator" in which compartment he had to put the card.
Machine sorter
The Tabulating Machine Company supplied the first 20 automatic sorting machines to the US Census Bureau in October 1901. The age of data processing automation began.
From 1908 Hollerith produced a revision of the sorter, he created a vertical machine, the (IBM) Hollerith 070 Vertical Sorter , which "didn't take up too much space in small railway offices". This achieved an output of 250 cards per minute. It was followed in 1928 by the more compact and less expensive model 071 , which could sort 150 cards per minute.
The 080, introduced in 1925, was the first device to have magnetically controlled turnouts and was able to almost double its output to 450 cards per minute. The 075 Counting Sorter , published in 1929, corresponded to the 080 with an additional panel with a counter per compartment, so that the number of perforations could be counted.
In 1948 the punched card sorter 082 appeared as a further development of the model 080 with an output of 650 cards per minute and a panel that was in line with contemporary tastes.
The IBM 083 model came onto the market from 1958 and was able to sort approx. 1000 cards per minute. The IBM 084 model came onto the market in 1960 and was able to sort around 2000 cards per minute.
Punch card sorters weren't just made by IBM. In the early 1960s , the Maul company from Schwabach specialized in small tabletop devices. The smallest version only had 6 compartments. The first 5 picked up the cards with holes for 0..4 or 5..9, the sixth cards without holes in the selected area. Numerical sorting processes could thus be carried out with 2 runs per column. In addition, the columns 10/11/12 could be selected to enable alphanumeric searches. With a width of less than one meter, all relevant search and sorting processes could be carried out directly in the office.
End of the punch card era
From the mid-1960s, magnetic tapes began to spread as a medium for storing and sorting data in data centers. They were faster and had a much higher capacity in terms of volume and weight. In the mid-1970s, the punch card was practically non-existent and was also replaced by magnetic tape cassettes and / or diskettes for data acquisition, for example . In line with this technological development, punch card sorters also disappeared from the data centers.
Punch card sorting process
Punched card sorters are a mechanical implementation of compartment distribution, also called radix sort .
Described here on the most commonly used type of punched card (80 columns, the decimal digits 0 to 9 plus two over-holes per column) and essentially with reference to the IBM 082/083 sorter .
technical description
- The punch cards were placed as a stack in the input compartment. It held approx. 1000-3000 punch cards, depending on the design.
- Mechanical switches were used to set which column should be sorted and how. Zone or number sorting.
- The individual cards were pulled from the bottom of the stack using rubber rollers .
- The punch card code was identified in the column to be processed via electrical contacts (on a brush or a “knife roller”) in the reading position .
- According to the read code and the settings made, the read card was fed into one of the 13 output compartments with the aid of rollers, electrically and mechanically, with some devices also magnetically via a guide : for 0–9, for the two over-hole zones and for 'empty '.
- Several partial stacks of punched cards were formed there, which were fed back to the next sorting steps or (at the end of the sorting) could be used for processing.
Depending on the performance of the sorter, it could sort several thousand punch cards per minute in one pass. Since the cards were moved physically and visibly, this was - z. B. for visitors to data centers - an impressive demonstration of the "efficiency of modern technology".
Another schematic representation for the code scanning and for the control of the storage compartments, valid for the IBM-082 sorter, can be found in the web links.
Sequence of sorting processes
The operators of the sorter usually worked according to specifications in which, for each sorting process, it was precisely described which punch card stacks are to be sorted according to which columns, in which order and how (numeric or alphanumeric; ascending or descending).
The sorting settings were made before each column was sorted: Column to be sorted; which storage compartments control? The input cards had to be added to the input compartment until all cards had run through. The partial stacks of punched cards issued in the output trays had to be fed to the next sorting run in the correct order; In the case of large amounts of data, it was necessary to store it in intermediate compartments (cupboard). This required a high level of concentration, because in the event of errors (stack falls down - a "catastrophe"), the entire sorting run (across all columns) usually had to be repeated.
In the case of multi-column sorting, one sorting run was required for each column. It started with the least significant column, then sorted the second lowest, and so on - up to the most significant column. Sorting z. B. by date (YYMMDD) ran from right to left. The web link "Function diagram" shows details.
Numerical sorting
In the case of columns with only numerical content, one sort pass per column was sufficient. The partial stacks of cards 0 to 9 were completely sorted (with 1-digit sorting) or had to be presented again in exactly the order 0 to 9 for sorting the next column.
Alphanumeric sorting
The individual column had to be sorted in several (up to four) runs. The first run resulted in a sorting according to the over-perforations including zero. Further runs for the same column, but according to the decimal values belonging to the over-punching and separately for each zone value, ultimately resulted in the desired card sequence.
Sort out
Certain punch cards had to be sorted out from a pile of punch cards. Example: The 'postings' had to be sorted out from the already processed pile of punched cards, which also contained address and account master data. The stacks of results could then be further processed separately or transferred to the punch card archive. Prerequisite: The cards to be sorted out must be clearly recognizable in one or more columns. In addition, a so-called 'type of card' was often included in the first digits of the punch card.
From a technical point of view, sorting out was a variant of sorting: It was only set so that only punch cards with a certain content were placed in the storage compartment, all others in the remaining compartment.
Manual (English, PDF)
Sorting
- IBM: IBM 83 Sorter: Manual of Operation December, 1959, 222-66395-5.
Web links
- Data center with 2 full sorting
- Function diagram
- Sorter from Maul
- Scheme for code scanning and control in storage compartments
Individual evidence
- ^ IBM: "Horizontal Sorter" IBM Archive 1901 in English
- ↑ IBM: "(IBM) Hollerith 070" IBM archive in English
- ↑ IBM: IBM Type 080 IBM Archive in English
- ↑ Robotron technology: data carrier / memory , accessed on July 20, 2012
- ↑ Bernhard Engstler: Media Technology Seminar (PDF; 1.3 MB) Retrieved on July 20, 2012