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IBM 728
The IBM 728 magnetic tape drive was used on the SAGE AN/FSQ-7 computer. It was physically similar to the IBM 727, but with significantly different specifications. This is one of several IBM 7 track tape drives. Tape Word Bit Positions -----------------------------> Tape travel LS L6 L12 R2 R8 R14 L1 L7 L13 R3 R9 R15 L2 L8 L14 R4 R10 P SYN SYN SYN SYN SYN SYN L3 L9 L15 R5 R11 EOF L4 L10 RS R6 R12 EOF L5 L11 R1 R7 R13 EOF -----------------------------> Tape travel 728 __NOTOC__ Year 728 ( DCCXXVIII) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar. The denomination 728 for this year has been used since the early medieval period, when the Anno Domini calendar e ... Tape 728 {{compu-storage-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AN/FSQ-7
The AN/FSQ-7 Combat Direction Central, referred to as the Q7 for short, was a computerized command and control system for Cold War ground-controlled interception used in the USAF Semi-Automatic Ground Environment (SAGE) air defense network. The name “AN/FSQ” derives from ''Army-Navy / Fixed Special eQuipment''. An advancement of the pioneering MIT Whirlwind II digital computer design, and manufactured by IBM as prime contractor, the AN/FSQ-7 was the largest discrete computer system ever built. Each of the 24 installed machines weighed 250 tons. The AN/FSQ-7 used a total of 60,000 vacuum tubes (49,000 in the computers) and up to 3 megawatts of electricity, performing about 75,000 instructions per second for networking regional radars. Primary functions Installations in the USAF Semi-Automatic Ground Environment (SAGE) air defense network were configured as duplex systems, using a pair of AN/FSQ-7 computers to provide fault tolerance. One was active at any time, the other on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 727
The IBM 727 Magnetic Tape Unit was announced for the IBM 701 and IBM 702 on September 25, 1953. It became IBM's standard tape drive for their early vacuum-tube era computer systems. Later vacuum-tube machines and first-generation transistor computers used the IBM 729-series tape drive. The 727 was withdrawn on May 12, 1971. The tape had seven parallel tracks – six for data and one to maintain parity. Tapes with character data ( BCD) were recorded in even parity. Binary tapes used odd parity. Aluminum strips were glued several feet from the ends of the tape to serve as logical beginning and end of tape markers. Write protection Write protection is any physical mechanism that prevents writing, modifying, or erasing data on a device. Most commercial software, audio and video on writeable media is write-protected when distributed. Examples * IBM -inch magnetic tape r ... was provided by a removable plastic ring in the back of the tape reel. References 727 Tape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 7 Track
IBM's first magnetic-tape data storage devices, introduced in 1952, use what is now generally known as 7-track tape. The magnetic tape is 1/2" wide, and there are six data tracks plus one parity track for a total of seven parallel tracks that span the length of the tape. Data is stored as six-bit characters, with each bit of the character and the additional parity bit stored in a different track. These tape drives were mechanically sophisticated floor-standing drives that used vacuum columns to buffer long U-shaped loops of tape. Between active control of powerful reel motors and vacuum control of these U-shaped tape loops, extremely rapid start and stop of the tape at the tape-to-head interface could be achieved. When active, the two tape reels thus fed tape into or pulled tape out of the vacuum columns, intermittently spinning in rapid, unsynchronized bursts resulting in visually striking action. Stock shots of such vacuum-column tape drives in motion were widely used to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
