.bcn

.bcn is a generic top-level domain for the city of Barcelona, Catalonia, Spain.

References

Type B videotape

1 inch type B VTR (designated Type B by SMPTE) is a reel-to-reel analog recording video tape format developed by the Bosch Fernseh division of Bosch in Germany in 1976. The magnetic tape format became the broadcasting standard in continental Europe, but adoption was limited in the United States and United Kingdom, where the Type C videotape VTR was met with greater success.

The tape speed allowed 96 minutes on a large reel (later 120 minutes), and used 2 record/playback (R/P) heads on the drum rotating at 9000 RPM with a 190 degree wrap around a very small head drum, recording 52 video lines per head segment. Video is recorded on an FM signal with a bandwidth of 5.5 MHz. Three longitudinal audio tracks are recorded on the tape as well: two audio and one Linear timecode (LTC) track. BCN 50 VTRs were used at the 1980 Summer Olympics in Moscow

The format required an optional, and costly, digital framestore in addition to the normal analog timebase corrector to do any "trick-play" operations, such as slow motion/variable-speed playback, frame step play, and visible shuttle functions. This was because, unlike 1 inch type C which recorded one field per helical scan track on the tape, Type B segmented each field to 5 or 6 tracks per field according to whether it was a 525 (NTSC) or 625 (PAL) line machine.

BCN

BCN may refer to:

ZPU

The ZPU (Russian: зенитная пулемётная установка, meaning "anti-aircraft machine gun mount") is a family of towed anti-aircraft gun based on the Soviet 14.5×114mm KPV heavy machine gun. It entered service with the Soviet Union in 1949 and is used by over 50 countries worldwide.

Quadruple (ZPU-4), two double- (ZPU-2 and ZU-2) and single-barreled (ZPU-1) versions of the weapon exist.

Precursor

The first dedicated Soviet mount for anti-aircraft machine guns was developed around 1928 by Fedor Tokarev and was adopted for service in 1931. It was a base for mounting up to four 7.62 mm PM M1910 (Russian Maxim) guns. This was also called a ZPU, although the name М-4 was also assigned to it. It served the Soviet armed forces in all major conflicts until 1945.

Description

Development of the ZPU-2 and ZPU-4 began in 1945, with development of the ZPU-1 starting in 1947. All three were accepted into service in 1949. Improved optical predicting gunsights were developed for the system in the 1950s.

All weapons in the ZPU series have air-cooled quick-change barrels and can fire a variety of ammunition including API (B32), API (BS41), API-T (BZT) and I-T (ZP) projectiles. Each barrel has a maximum rate of fire of around 600 rounds per minute, though this is practically limited to about 150 rounds per minute.

ZPU (microprocessor)

The ZPU microprocessor is a stack machine designed to run supervisory code in electronic systems that include a field-programmable gate array (FPGA).

The ZPU is notable because it is a relatively recent stack machine with a small but real economic niche, and it has a growing number of users and implementations. Many experts think that this is impossible.

The ZPU has been designed to require very small amounts of electronic logic, making more electronic logic available for other purposes in the FPGA. To make it easily usable, it has a port of the GNU Compiler Collection. This makes it much easier to apply than CPUs without compilers.

The ZPU is very small, but it is not fast. It keeps the intermediate results of calculations in memory, in a push-down stack, rather than in registers.

Zylin Corp. made the ZPU open-source in 2008.

Usage

Many electronic projects include electronic logic in an FPGA. It's wasteful to also have a microprocessor, so it is commonplace to add a CPU to the electronic logic in the FPGA. Often, a smaller, less-expensive FPGA could be used if only the CPU used less resources. This is the exact situation that the ZPU was designed to address.