Z-100 (computer)
Encyclopedia
The Z-100 computer was an early microcomputer
made by Zenith Data Systems
(ZDS). It was a pre-assembled version of the Heathkit
(recently purchased by Zenith Electronics
to become ZDS) H-100, which left the final component assembly to early computer hobbyists.
Z-100 Computers were early personal computer (PC) era alternatives to the hardware system that won the marketing shares war in the early to mid 1980s, the IBM PC
/XT/AT succession or family of computers. Configured as a family (Z-120 was an all in one model, with self-contained monitor), the Z-110 (called the low profile model) was similar in size to the cabinet of an IBM PC, XT, or AT, but a bit shorter, and configured with a raised cabinet molding on the top surface within which one placed one's display monitor, designed to keep it from sliding off to either side or back. Both models had a built in keyboard that was tactilely and in appearance modeled on an IBM Selectric typewriter
, the premier office machine of the day. The keyboard had a wonderful "feel" and "stroke action" that Byte Magazine columnist and fiction author Jerry Pournelle
raved about in several columns.
The Z-100 was a "near-compatible" system to the IBM PC, using standard floppy drives. It ran a non-IBM version of MS-DOS, so "generic MS-DOS" programs would run; but most commercial PC software used IBM BIOS
extensions and would fail. Several companies offered software or hardware solutions to permit unmodified PC programs to work on the Z-100.
The Z-100 had superior graphics to the contemporary CGA
(640x200 monochrome bitmap or 320x200 4-color), IBM Monochrome Display Adapter (80x25 text-only), and arguably even the Hercules Graphics Card
(720x348 monochrome). Early versions of AutoCAD
were released for the Z-100 because of these advanced graphics.
Aftermarket vendors also released modifications to upgrade mainboard memory and permit installation of an Intel 8087
math coprocessor.
In 1983, Clarkson College of Technology
(now Clarkson University) required all incoming freshmen to purchase a Z-100 computer as part of their entry requirement, making it one of the first institutions to mandate computers for its students.
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
made by Zenith Data Systems
Zenith Data Systems
Zenith Data Systems was a division of Zenith founded in 1979 after Zenith acquired Heathkit, which had, in 1977, entered the personal computer market. Headquartered in Benton Harbor, Michigan, Zenith sold personal computers under both the Heath/Zenith and Zenith Data Systems names...
(ZDS). It was a pre-assembled version of the Heathkit
Heathkit
Heathkits were products of the Heath Company, Benton Harbor, Michigan. Their products included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, electronic ignition conversion modules for early model cars with point style ignitions, and...
(recently purchased by Zenith Electronics
Zenith Electronics
Zenith Electronics Corporation is a brand of the South Korean company LG Electronics. The company was previously an American manufacturer of televisions and other consumer electronics, and was headquartered in Lincolnshire, Illinois. LG Electronics acquired a controlling share of Zenith in 1995...
to become ZDS) H-100, which left the final component assembly to early computer hobbyists.
Z-100 Computers were early personal computer (PC) era alternatives to the hardware system that won the marketing shares war in the early to mid 1980s, the IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
/XT/AT succession or family of computers. Configured as a family (Z-120 was an all in one model, with self-contained monitor), the Z-110 (called the low profile model) was similar in size to the cabinet of an IBM PC, XT, or AT, but a bit shorter, and configured with a raised cabinet molding on the top surface within which one placed one's display monitor, designed to keep it from sliding off to either side or back. Both models had a built in keyboard that was tactilely and in appearance modeled on an IBM Selectric typewriter
IBM Selectric typewriter
The IBM Selectric typewriter was a highly successful model line of electric typewriters introduced by IBM on July 31, 1961.Instead of the "basket" of individual typebars that swung up to strike the ribbon and page in a traditional typewriter, the Selectric had a type element that rotated and...
, the premier office machine of the day. The keyboard had a wonderful "feel" and "stroke action" that Byte Magazine columnist and fiction author Jerry Pournelle
Jerry Pournelle
Jerry Eugene Pournelle is an American science fiction writer, essayist and journalist who contributed for many years to the computer magazine Byte and has since 1998 been maintaining his own website/blog....
raved about in several columns.
- Dual processors: 8085Intel 8085The Intel 8085 is an 8-bit microprocessor introduced by Intel in 1977. It was binary-compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built....
and 8088Intel 8088The Intel 8088 microprocessor was a variant of the Intel 8086 and was introduced on July 1, 1979. It had an 8-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range were unchanged, however... - Available with CP/MCP/MCP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
and Z-DOSZ-DOSZ-DOS was a version of Microsofts generic MS-DOS specifically written to run on the hardware of the Zenith Z-100 personal computer.The Z-100 used a 8086-family microprocessor, but otherwise had a completely different internal architecture than the IBM PC.At the time Microsofts MS-DOS wasn't...
(non-IBM compatible MS-DOSMS-DOSMS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
variant) - Five S-100S-100 busThe S-100 bus or Altair bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer...
expansion slots - Two 320KB 40-track double-sided 5.25-inch Floppy diskFloppy diskA floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
drives. Socket enabled direct plug-in of external 8-inch floppies. - 2x serialRS-232In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
ports (2661 UARTUniversal asynchronous receiver/transmitterA universal asynchronous receiver/transmitter, abbreviated UART , is a type of "asynchronous receiver/transmitter", a piece of computer hardware that translates data between parallel and serial forms. UARTs are commonly used in conjunction with communication standards such as EIA RS-232, RS-422 or...
), one Centronics printer port (discrete TTL chips), light penLight penA light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy...
port - 640x225 bitmap display. 8 colors (low-profile model), or monochrome upgradable to 8 greyscales (all-in-one).
- Base 128k RAM, expandable to 192K on-board, to 768K with S-100 cards. (Video RAM was paged into the 64K block above 768K).
The Z-100 was a "near-compatible" system to the IBM PC, using standard floppy drives. It ran a non-IBM version of MS-DOS, so "generic MS-DOS" programs would run; but most commercial PC software used IBM BIOS
BIOS
In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
extensions and would fail. Several companies offered software or hardware solutions to permit unmodified PC programs to work on the Z-100.
The Z-100 had superior graphics to the contemporary CGA
Color Graphics Adapter
The Color Graphics Adapter , originally also called the Color/Graphics Adapter or IBM Color/Graphics Monitor Adapter, introduced in 1981, was IBM's first color graphics card, and the first color computer display standard for the IBM PC....
(640x200 monochrome bitmap or 320x200 4-color), IBM Monochrome Display Adapter (80x25 text-only), and arguably even the Hercules Graphics Card
Hercules Graphics Card
The Hercules Graphics Card was a computer graphics controller made by Hercules Computer Technology, Inc. which, through its popularity, became a widely supported display standard. It was common on IBM PC compatibles connected to a monochrome monitor . It supported one high resolution text mode and...
(720x348 monochrome). Early versions of AutoCAD
AutoCAD
AutoCAD is a software application for computer-aided design and drafting in both 2D and 3D. It is developed and sold by Autodesk, Inc. First released in December 1982, AutoCAD was one of the first CAD programs to run on personal computers, notably the IBM PC...
were released for the Z-100 because of these advanced graphics.
Aftermarket vendors also released modifications to upgrade mainboard memory and permit installation of an Intel 8087
Intel 8087
The Intel 8087, announced in 1980, was the first floating-point coprocessor for the 8086 line of microprocessors. It had 45,000 transistors and was manufactured as a 3 μm depletion load HMOS circuit. The 8087 was built to be paired with the Intel 8088 or 8086 microprocessors...
math coprocessor.
In 1983, Clarkson College of Technology
Clarkson University
-The Clarkson School:The Clarkson School, a special division of Clarkson University, was founded in 1978 as a unique educational opportunity. The School offers students an early entrance opportunity into college, replacing the typical senior year of high school with a year of college...
(now Clarkson University) required all incoming freshmen to purchase a Z-100 computer as part of their entry requirement, making it one of the first institutions to mandate computers for its students.
External links
- Z-100 information and pictures from the DigiBarn Computer MuseumDigiBarn Computer MuseumThe DigiBarn Computer Museum, or simply DigiBarn, is a computer history museum in Boulder Creek, California, United States. The museum is housed in a 90-year-old barn constructed from old-growth Redwood in the Santa Cruz Mountains, which is adjacent to Silicon Valley...