Cromemco Z-2
Encyclopedia
Z-2 was the name of a series of microcomputer
made by Cromemco
, Inc. which were produced in the middle to late 1970s.
They were available in assembled or kit form and, although primarily intended for a business market, achieved some popularity among early computer enthusiasts owing to their speed, configurability, and durability.
CPU card, S-100 bus
motherboard
, all-metal rack-mount chassis and dust case, card socket and card guide; The assembled form included in addition a complete set of sockets and card guides, and a cooling fan. The Z-2 series was capable of supporting up to 21 S-100 boards and could be configured with any of the boards supplied by Cromemco.
The Z-2 gave an impression of solidity due to its hefty 450-watt power supply
and heavy metal chassis. A TU-ART (dual serial and parallel board), 4FDC Floppy Disk Controller
, one or more 16KZRAM cards, and a Wangco 5¼" floppy disk drive would be added to form a basic system.
An unusual feature of the Z-2 was switch selectable CPU speed; 250 or 500 nanosecond
cycle time were provided. The ZPU speed was 4 MHz at a time when less than 2 MHz was normal, and boards from other manufacturers might still require the slower speed. The ZPU card in the Z-2 could address up to 64 kilobyte
s of RAM. However, the 16KZ memory card supported bank-switching with 8 banks of 64 kilobytes each. When using the 16KZ, the maximum RAM of the Z-2 was limited by the available S-100 slots. If 16 of the slots were occupied by 16KZ cards, then the system had 4 banks of 64 kilobytes each, for a total of 256 kilobytes.
Additional S-100 slots were required for cards controlling peripherals, disk drives, and I/O interfaces. Communication with the processor was normally performed through a TU-ART or other S-100 bus compatible interface card, which could run a CRT terminal or teletype.
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 Cromemco
Cromemco
Cromemco was a Mountain View, California microcomputer company known for its high-end Z80-based S-100 bus computers in the early days of the home computer revolution. The Cromemco Dazzler was the first color graphics card available for personal computers....
, Inc. which were produced in the middle to late 1970s.
They were available in assembled or kit form and, although primarily intended for a business market, achieved some popularity among early computer enthusiasts owing to their speed, configurability, and durability.
Cromemco Z-2
The Cromemco Z-2 computer was a Z80 based microcomputer system produced in the middle to late 1970s. The original Z-2 in kit form included a ZPU-K Z80Zilog Z80
The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...
CPU card, S-100 bus
S-100 bus
The 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...
motherboard
Motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
, all-metal rack-mount chassis and dust case, card socket and card guide; The assembled form included in addition a complete set of sockets and card guides, and a cooling fan. The Z-2 series was capable of supporting up to 21 S-100 boards and could be configured with any of the boards supplied by Cromemco.
The Z-2 gave an impression of solidity due to its hefty 450-watt power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
and heavy metal chassis. A TU-ART (dual serial and parallel board), 4FDC Floppy Disk Controller
4FDC Floppy Disk Controller
The Cromemco 4FDC Floppy Disk Controller is designed to interface both 5- and 8-inch floppy disk drives to the S-100 computer bus used in Cromemco and other IEEE 696 computers. It also contains an RS232 serial I/O channel with software-selectable baud rates from 110 to 76,800...
, one or more 16KZRAM cards, and a Wangco 5¼" floppy disk drive would be added to form a basic system.
An unusual feature of the Z-2 was switch selectable CPU speed; 250 or 500 nanosecond
Nanosecond
A nanosecond is one billionth of a second . One nanosecond is to one second as one second is to 31.7 years.The word nanosecond is formed by the prefix nano and the unit second. Its symbol is ns....
cycle time were provided. The ZPU speed was 4 MHz at a time when less than 2 MHz was normal, and boards from other manufacturers might still require the slower speed. The ZPU card in the Z-2 could address up to 64 kilobyte
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
s of RAM. However, the 16KZ memory card supported bank-switching with 8 banks of 64 kilobytes each. When using the 16KZ, the maximum RAM of the Z-2 was limited by the available S-100 slots. If 16 of the slots were occupied by 16KZ cards, then the system had 4 banks of 64 kilobytes each, for a total of 256 kilobytes.
Additional S-100 slots were required for cards controlling peripherals, disk drives, and I/O interfaces. Communication with the processor was normally performed through a TU-ART or other S-100 bus compatible interface card, which could run a CRT terminal or teletype.