The IBM 2741 became closely associated with the APL programming language. As originally proposed by Dr. Kenneth Iverson, APL required a large variety of special characters. IBM implemented it as a timesharing system on the IBM System/360, calling it APL\360. It required the use of an IBM 2741  or IBM 1050 with an APL typeball. There were only 26 alphabet characters,  all displayed as upper case italic, even though they were typed with the machine in lower case mode. The "shifted" keystroke characters provided many of the special symbols with the remainder being handled by overstrike. Keyboard layout with the APL typeball print head inserted:  Similar to APL, ALGOL 68 was defined with a large number of special characters. Many of them  ( ∨, ∧, ¬, ≠, ≤, ≥, ×, ÷, ⌷, ↑, ↓, ⌊, ⌈ and ⊥ ) were available on the APL Selectric typeball, so this element was  used to prepare the ALGOL 68 programming language standard Final Report (August 1968),  even though APL and ALGOL have no direct relationship. The IBM 2740 is a similar terminal that lacked the interrupt feature and dialup capability, but is capable of operating in point-to-point, multipoint or broadcast mode. For the better use of multipoint lines, it could add a data buffer, letting the line run at 600bit/s without being constrained by the speed of the typing mechanism. Some later IBM Selectric-based machines, such as the Communicating Magnetic Card Selectric Typewriter, can emulate the 2741 and be used in its place. IBM sold the underlying Selectric mechanism to other manufacturers, who produced 2741 clones at lower cost. Some of these were integrated into larger systems instead of being sold as standalone terminals. For example, a 2741-type mechanism formed the principal user interface for a series of machines from the 1960s and 1970s built in the United Kingdom by Business Computers Ltd. The 2741 and similar Selectric-based machines were supplanted by ASCII terminals using the Xerox Diablo 630 "daisy wheel" and similar print mechanisms where hard copy was required. These offered equivalent print quality, better reliability, twice the speed (30 char/s), and lower cost than the 2741. They could use a variety of fonts (including APL) via interchangeable print wheels  and, unlike the 2741, supported the entire ASCII printing character set.