in a distinctive "chunk, chunk" sound as columns were punched. Both machines could process 51-, 60-, 66-, and 80-column cards. The 026 could print the punched character above each column. By 1964 there were ten versions with slightly different character sets. The scientific versions printed parentheses, equal sign and plus sign in place of four less frequently used characters in the commercial character sets. Logic consisted of diodes, 25L6 vacuum tubes and relays. The tube circuits used 150VDC, but this voltage was only used to operate the punch-clutch magnet. Most other circuits used 48VDC. Characters were printed using a 5 × 7 dot matrix array of wires; the device from which it derived the shape of the character was a metal plate, called the "code plate," with space for 1960 pins (35 pins times 56 printable characters). If the dot was not to be printed in a given character, the pin was machined off. By correctly positioning the plate and pressing it against one end of the array of printing wires, only the correct wires were pressed against the ribbon and then the punched card. (This printer mechanism was generally considered by IBM Customer Engineers to be difficult to repair. One of the most common problems was wires breaking in the tightly curved narrow tube between the code plate and the ribbon—extracting the fragments and replacing the bundle of 35 wires was very tedious). The printing mechanism was prone to be damaged if a user attempted to duplicate "binary" cards with non-standard punch patterns. These could cause the code-plate positioning mechanism to try to shift the plate beyond its intended range of motion, sometimes causing damage. Turning off printing did not actually prevent the damage, as many people assumed, because the code-plate mechanism remained engaged with the punch unit and shifted the code plate. Turning off printing only suppressed pressing the printing pins into the ribbon and card. Raymond Loewy, industrial designer of "streamlined" motifs who also designed railway passenger cars of the 1930s and 1940s, did the award-winning external design of the 026/024 Card Punches for IBM. Their heavy steel construction and rounded corners (photos) indeed echo the industrial Art Deco style. IBM 056 Card Verifier The IBM 056 was the verifier companion to the 024 Card Punch and 026 Printing Card Punch. The verifier was similar to the 026 keypunch except for a red error lens in the