can be done at a much higher speed, and a faster print mechanism is needed to match the resulting productivity. IBM's early computers, such as the IBM 701, were developed for higher speed calculation than was possible with earlier electromechanical calculating machines. They did not have a demand for high speed printing, as the results of massive calculations produced very little printed output. Around the time that the 1403 was introduced, IBM's line of computers had been largely divided into two lines, "scientific" and "business." However, as newer computers were being used for a greater variety of purposes, there was a need to print a greater variety of characters from a single device, including upper and lower case alphabets. With type bars and type wheels, changing character sets is impractical. The advent of the chain printer, as used in the 1403, allows the type chain assembly to be removed and replaced within a few minutes. With the cover open, the print unit is unlatched and swung open, the ribbon roll covering the front of the chain is removed, whereupon the print chain assembly can be unlatched and lifted out. When it was first introduced, the 1401 computer system, of which the printer was a part, leased for $6500 per month (equivalent to $54,000 in 2017) and IBM received 3000 orders in the first month. Technology Chain printing allows a single set of characters to pass horizontally across the front of the paper at high speed, with a ribbon the full width of the paper passing vertically between the chain and the front of the paper. Instead of pressing the characters toward the paper, individual type hammers behind the paper, one for each column on the page (120 or 132), push the paper from behind, causing the front of the paper at that spot to push forward into the ribbon with the character behind it, causing the paper to strike the character, rather than the other way around, as had been done in the past. Each hammer is moved by a powerful electromagnet, with its coil connected to a high current drive circuit, such that the hammer can be forced out to hit the paper within only a few milliseconds, at exactly the right time to strike the correct character on the chain as it came by. The columns on the paper are spaced at the standard typewriter pitch of 10