Zi from FOLDOC

ZIF

zigamorph

/zig'*-morf/ 1. Hex FF (11111111) when used as a delimiter or fence character. Usage: primarily at IBM shops.

2. [proposed] The Unicode non-character +UFFFF (1111111111111111), a character code which is not assigned to any character, and so is usable as end-of-string.

[Jargon File]

ZIL

<games>

Zork Implementation Language. Language used by Infocom's Interactive Fiction adventure games. Interpreted by the zmachine, for Unix and Amiga.

ftp://plains.nodak.edu/Minix/st.contrib.Infocom.tar.Z.

Zilog

<company>

The microprocessor manufacturer who produced the Zilog Z80 in July 1976 (as used by Sinclair in the ZX-80, ZX-81 and ZX Spectrum computers) and later the Zilog Z8000.

Zilog was founded in 1974 and became a wholly owned subsidiary of Exxon Corp. by 1980. The company's management and employees purchased Zilog back from Exxon in 1989. Zilog became a publicly-held company in February, 1991. In March of 1998, Zilog was privatised, as a result of the merger and recapitalisation transaction by Texas Pacific Group (TPG).

Zilog now produce a range of 8-bit microcontrollers, 8-, 16- and 32-bit microprocessors, and digital signal processors, covering the home entertainment, communications, and embedded systems markets.

http://zilog.com/.

Address: 910 East Hamilton Avenue, Suite 110, Campbell, CA 95008, USA.

Last updated: 1998-09-14

Zilog Z280

An enhanced version of the Zilog Z80 with a 16 bit architecture, introduced in July, 1987. It added an MMU to expand addressing to 16Mb, features for multitasking, a 256 byte cache, and a huge number of new op codes (giving a total of over 2000!). Its internal clock runs at 2 or 4 times the external clock (e.g. a 16MHz CPU with a 4MHz bus).

Last updated: 1994-10-31

Zilog Z8

<processor>

A family of microcontrollers from Zilog with on-chip RAM and ROM. The Z8 is not related to the Zilog Z80, it uses a totally different architecture and instruction set.

Competitors include the Motorola 6805/68HC05 family or the Intel 8051-family (or i51-family or MCS51-family - there is no standard family name).

Last updated: 1995-04-22

Zilog Z80

<processor>

An 8-bit microprocessor. It was released in July 1976 with a 2.5 MHz clock rate. The Z80 was a much improved Intel 8080 (as was the Intel 8085). It also used 8-bit data and 16-bit addressing, and could execute all of the 8080 op codes as well as 80 new ones, instructions that included 1, 4, 8 and 16-bit operations and even block move and block I/O instructions. The register set was doubled, with two banks of registers (including A and F) that could be switched between. This allowed fast operating system or interrupt context switches. It features 3 types of interrupt mode.

The Z80 also added two index registers (IX and IY) and relocatable vectored interrupts (via the 8-bit IV register). Like many processors (including the 8085), the Z80 featured many undocumented op codes. Chip area near the edge was used for added instructions, but fabrication made the failure of these high. Instructions that often failed were just not documented, increasing chip yield. Later fabrication made these more reliable.

The thing that really made the Z80 popular was the memory interface - the CPU generated it's own RAM refresh signals, which meant easier design and lower system cost. That and its 8080 compatibility and CP/M, the first standard microprocessor operating system, made it the first choice of many systems.

In addition to the original Z80 (2.5 MHz) there are the Zilog Z80A (4 MHz), Zilog Z80B (6MHz) and Zilog Z80H (8 MHz) versions. The popular Hitachi HD64180 processor family adds peripherals and an MMU to the Z80.

The Zilog Z280 was an enhanced version with an MMU and many new op codes.

The Z80 was used in the first Nintendo Game Boy. A Sharp Z80 work-alike was used in the GameBoy Color, running at 4 MHz for GameBoy software or at 8 MHz for Game Boy Color software. The Z80 was used in the Sega Master System and the Game Gear. It was also used in the Sega Genesis for hardware reverse compatibility with the Sega Master System through a special cartridge.

Gaby Chaudry site.

Last updated: 2004-06-10

Zilog Z8000

<processor>

A microprocessor from Zilog introduced not long after the Intel 8086, but with superior features. It was basically a 16-bit processor, but could address up to 23 bits in some versions by using segment registers (to supply the upper 7 bits). There was also an unsegmented version, but both could be extended further with an additional MMU that used 64 segment registers.

Internally, the Z8000 had sixteen 16-bit registers, but register size and use were exceedingly flexible. The Z-8000 registers could be used as sixteen 8-bit registers (only the first half were used like this), sixteen 16-bit registers, eight 32-bit registers, or four 64-bit registers, and included 32-bit multiply and divide. They were all general purpose registers - the stack pointer was typically register 15, with register 14 holding the stack segment (both accessed as one 32-bit register for painless address calculations).

The Z8000 featured two modes, one for the operating system and one for user programs. The user mode prevented the user from messing about with interrupt handling and other potentially dangerous stuff.

Finally, like the Zilog Z80, the Z8000 featured automatic DRAM refresh circuitry. Unfortunately it was somewhat slow, but the features generally made up for that. Initial bugs also hindered its acceptance (partly because it did not use microcode). There was a radiation resistant military version.

There was a later 32-bit, pipelined version, the Zilog Z80000.

Last updated: 1997-12-16

Zilog Z80000

<processor>

A later version of the Zilog Z8000, expanded to 32 bits internally and with a 6-stage pipeline.

Last updated: 1997-12-16

Zilog Z80A

<processor>

A version of the Zilog Z80 microprocessor with a 4 MHz clock rate.

Last updated: 1995-04-24

zip

<tool, compression, file format>

1. A compressed archive containing one or more files, the act of creating it and its filename extension. Originally, such a "zip file" was created using PKWare, Inc.'s PKZIP utility program for MS-DOS.

Due to the popularity of the original program, the format has spread to Windows, Unix and other operating systems and the function is often built into file managers.

unzip is the corresponding de-archiver or the act of extracting files from an archive.

The first two bytes of a zip file are the ASCII characters "PK" after Phil Katz who developed the original PKZIP.

Zipcode

<language>

A parallel language at Lawrence Livermore(?).

Last updated: 1996-08-26

Zip disc

Zip drive

Zip disk

Zip drive

Zip Drive

<hardware, storage>

A disk drive from Iomega Corporation which takes removable hard disks storig 100 to 750 megabytes. Both internal and external drives are manufactured, making the drive suitable for backup, mass storage or for moving files between computers. Software is included to help with file organisation. The internal SCSI model offers up to 60 MB / minute transfer rate.

The Zip drive was awarded Byte's Readers' Hardware Choice Award 1996. It was superceded by the Jaz drive which takes one gigbyte disks.

Last updated: 2008-01-21