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