website/content/museum/cromemco-z-2.md

---
title: Cromemco Z-2
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1977'
cpus:
- Z80
params:
  name: Z-2
  company: /companies/cromemco
  company_name: Cromemco
  specs:
  - label: NAME
    value: Z-2
  - label: MANUFACTURER
    value: Cromemco
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: June 1977
  - label: CPU
    value: Z80
  - label: SPEED
    value: 4 Mhz.
  - label: RAM
    value: RAM and ROM sizes depended of the cards used
  - label: ROM
    value: 1 KB Monitor
  - label: TEXT MODES
    value: Depends on the video terminal used
  - label: I/O PORTS
    value: RS232C and Parallel interfaces
  - label: BUILT IN MEDIA
    value: Depends on the version
  - label: OS
    value: CP/M
  - label: POWER SUPPLY
    value: 8 V. and 18 V. integrated power supply
  - label: PERIPHERALS
    value: 21 x S-100 slots
  - label: PRICE
    value: 'Kit : $595 - Assembled : $995'
  tabs:
  - photos
  - adverts
  - hardware
  photos:
  - title: Z2D
    subtitle: ''
    text: |-
      The most popular Z2 version.\
      Expansion options include 512 KB 8" floppy drives, 11 or 22 MB hard disks ans high resolution graphics.
    image: null
  adverts:
  - title: Z-2 1977 ADVERT
    subtitle: ''
    text: 'Advert said: Cromemco microcomputers are the fastest and most powerful available. They use the Z80 microprocessor which is widely regarded as the standard of the future. So you''re in the technical fore with the Z-2'
    image: null
  - title: Z-2D ADVERT (1977)
    subtitle: ''
    text: |-
      Z-2D 1977 price list:

      \- Kit version with 1 F.D. drive: **$1495**\
      \- Assembled version: **$2095**\
      \- Additional F.D. drive: **$495**
    image: null
  - title: Z-2H 1980 ADVERT
    subtitle: ''
    text: ''
    image: null
  hardware:
  - title: SINGLE CARD COMPUTER
    subtitle: ''
    text: |-
      This all-in-one card offered:\
      \- a 4 Mhz. Z80 microprocessor\
      \- 8 Kb. ROM capacity (2716 PROM chips)\
      \- 1 Kb. on board static RAM\
      \- 76.800 bauds serial port\
      \- 24 bits bidirectional parallel I/O\
      \- 5 programmable timers

      1979 price: $450
    image: null
  comments:
  - author: Paul Hansknecht (United States)
    date: Wednesday 24th October 2018
    text: 'OK, one last post: The Z-2H still required a floppy disk to boot up CP/M and get the whole thing started. Slow! I eventually figured out a way to use Cromemco''''s 32KB E-PROM board and their Bank Switching capability to temporarily swap in the E-PROM board, copy a CP/M image from it to RAM. switch the E-PROM board back out and jump to CP/M''''s startup address. Wow, startup was now instantaneous! I should have passed that technique back to Cromemco. :('
  - author: Paul Hansknecht (United States)
    date: Wednesday 24th October 2018
    text: Oops, in my previous post, the Z-2H was announced in 1980, and we acquired one in early 1981, not 1971.
  - author: Paul Hansknecht (United States)
    date: Wednesday 24th October 2018
    text: I was the technical half of a two-man company in the 70s and early 80s. The other guy was the owner, the salesforce, and the money man. Our plan was to build turnkey systems for the "zillions of small companies that could profitably use a micro-computer but didn''t know it". So in the late 70s, we bought a Z-2D kit so I could get started. It had a 4MHz Z-80, 64KB of RAM, 2 DSDD 184KB floppy disk drives, and a Televideo 950(?) terminal! We equipped it with the Cromemco Assembler and their FORTRAN IV Compiler. It was a beast! But oh, those floppy disks! Constantly swapping them in and out... Put in the editor disk (WordStar?) to work on some program. Take it out and put in the Compiler. Take it out and put in the linker. Save the executable to a separate floppy Test it. Repeat till satisfied. We knew most businesses would have a hard time keeping their program and data disks straight, but that was the best we could do. Then in 1971, Cromemco announced the Z-2H! OMG, 10MB! We swooned
      over the possibilities, and, unbelievably, the money man agreed to buy the add-on kit to convert our Z-2D to a Z-2H! We qualified as a Cromemco OEM at the time, so we got a 20$ or 25$ discount and paid a mere $7,500 (or something like that), and WOW! That completely changed the micro world! I could now "instantly" switch between an unlimited number of programs without touching a floppy disk! And that meant our customers could, too! This truly turned the microcomputer into a viable business solution overnight!
  - author: Christopher Shubert (USA)
    date: Monday 3rd April 2017
    text: |-
      I sold "micros" in Atlanta from 1979-1981, and Cromemco was one of the machines we sold. It was a tough sell because, although the Z2 was plainly a quality machine, the prices were substantially higher than other Z100 CP/M machines.

      The one piece of Cromemco hardware I recall selling was the amazing 10MB hard drive. What a wonder that was - super fast, and super-huge, compared to the standard 512K double-sided 8" floppies! (Then again, the case for the hard drive was gigantic, as well: a full-bay 14" monster!)

      But oh, the price tag on that hard drive. $10,000! Yes, seriously, someone actually plunked down $10K for 10MB! The guy who bought it was thrilled with the response time and the vast amount of space, but compare $1,000 per megabyte with modern storage costs!
  - author: Peter Fisk (Essex, England)
    date: Friday 25th February 2011
    text: |-
      I was part of a team that installed about six of these computers for use in the Health Service for word processing (Wordstar) and data capture. We wrote software to capture data about children''s vaccinations which could\
      then be sent via an accoustic modem to a mainframe system. The basic hardware was very reliable, but let down by unreliable external eight inch disk\
      floppy disk drives and poor quality modem links. The ''customers''\
      hated the data transmission but were happy to replace typewriters with Wordstar. A few lucky ones even got a daisywheel printer!
  - author: GCG$3 (Bob) (Yorktown, VA)
    date: Tuesday 27th April 2010
    text: I remember my excitement when we received our Z-2 during my senior year at El Capitan HS. We finally had an alternative to the school district''s HP2000F Time-Share system. My first project was to hack-together a Z80 version of Pong that I never got to work right. I was heart-broken when I heard it was stolen while I was away to Basic Training in 1979.
  - author: david wright (louisville, kentucky)
    date: Friday 18th February 2005
    text: In 1976 i was on the degsine team for this Cromemco Z2 system i had worked day and night i went without sleep for 15 days it was very very hard i had completed Cromemco Z2 system prototype but at a high price when we fired it up it blew up into a fire that destroyed my
  oc_id: 559
  source:
    url: https://web.archive.org/web/20230528105430/http://www.old-computers.com/museum/computer.asp?c=559
    date: '2023-05-28'
---

The Z2 system was an evolution of the Z1 model. Major change was a new CPU board using a 4 Mhz. Z80 microprocessor. The system, always based on the S-100 bus, proposed 21 connectors for S-100 cards and a stronger power supply able to supply additional peripherals. The front panel didn't offer any switches or control leds. 8080 based software made with the Z-1 model could run on the Z-2 system

The **Z2-D** (September 1977) version included 64 KB of RAM, one or two 92 KB (then 184 KB) formatted floppy drives and controller card.\
The **Z2-H** system appeared in July, 1980. Using the Z-2 basis but including a 11 MB hard disk, two dual sided floppy disc drives and 64 KB of RAM memory.