About the project …

This blog documents the making of my own Z80 CPU based computer.  The goal of the project is to make a fully functional 8-bit computer system from scratch, based on a classic 8-bit microporcessor. The computer should have a keyboard input and a monitor output.

In terms of specifications and capabilities of the computer, I`m aiming to achieve most of the functionality of late  70`s and early 80`s home computers like Apple 1, ZX80/ZX81, Commodore PET, Tandy TRS-80.

The computer is designed and built completly from scratch, using commonly available parts. No ready to use modules are used. The operating system / BIOS is written in Z80 assembly language.

This diagram represents the current system hardware configuration overview:


Current Software Features:

ROM Monitor with support for:

  • Screen and keyboard handling routines.
  • Memory manipulation (edit,dump,fill,copy).
  • Data downloading/uploading via UART and Parallel Port.
  • Direct input/output commands for I/O devices.
  • FAT16 basic operations on files.
  • Various utility routines (arthmetic, data type conversions, delays).
  • User code execution

CP/M 2.2 operating system installed

Current plans and research topics:

  • Support for  VGM file format (Video Game Music).
  • Changing display to 8-bit ISA VGA

11 thoughts on “About the project …”

  1. Leonard said:

    Nice Job! Remember the first S100 computers? Have a look at this
    http://s100computers.com/ Maybe get some ideas. . .
    I, too, have tried (successfully) from scratch; it’s a lot of work.


    • Hi! Thanks for comment. Shure I know S100 computers site! Great deal of inpiration. Great times as well. If you have some project of your own, please share it! I always enjoy looking at other people`s projects.


  2. This is so awesome! Keep up the good work!


  3. Hi, I’m working on a similar computer Z8T. http://elektronika2011.cz/z8t


  4. Jose Apache said:

    Learning at each step… a lot work and great experience. Good job engineer…


  5. My hero! Incredible! very good job!


  6. you’re an inspiration for us


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s