a monochrome (9845A/S), then a high-performance monochrome (9845B/T) and a high performance color (9845C/T) model. The 9845 came with one tape drive, and optional second tape drive and 80 column wide thermal printer integrated into the base under the pillar-mounted display unit. All the 98x5, with the exception of the 9805, used DC200 cartridge tapes, instead of cassette tapes. The 9825, 9831, 9835, and 9845 all used the same I/O interfaces. the 9815 had a unique I/O interface. An ancestor of modern personal computers The HP 9800 series were developed by HP's Loveland division (Calculator Products Division), and later Fort Collins division (Desktop Computer Division). Early desktop computers were marketed as "Calculators" to make purchasing easier. At the time, some companies had different procedures for purchasing "Computers". They spawned development of HP series 80, namely HP 85 and HP 87, that were smaller BASIC language computers with CRT displays. They came from HP's Advanced Products Division based in Corvallis. For a short time in the late 1970s and early 1980s there was a class of similar desktop computers, such as the Tektronix 4051, IBM 5100 and Wang 2200 - before they were replaced in the marketplace by personal computers such as the Apple and IBM PC. HP 9830 HP 9830 uses HP 9830s were commonly employed at aerospace companies such as Boeing. They were also used by some school systems such as Arlington, Virginia, and Renton, Washington, which used pencil mark-sense cards with card readers to accommodate classroom use. An HP 9830 system with an integrated hard drive was also provided by HP in the early 1970s to National Real Estate Exchange, Inc., a small company in Florida, for its use in developing early real estate software. The U.S. Coast Guard devised a teletype message-forwarding system based on 9825As which were deployed as a working prototype for a subsequent purpose-built system, and also used them in the coordination of LORAN radionavigation transmitter chains. HP9825s were used in conjunction with Oscor software to score one-design yachting regattas in remote locations, such as the 1976 World Fireball championships in Nova Scotia, the World Windsurfing championships in 1976/1977 in Cancún and Bahamas, and also Laser championships. The HP9825 was selected because it was portable – the only alternatives were phone access to time sharing computers which was not reliable from these locations. HP 9830 description 9830s were built with a processor similar in