Solc, T.: Replika mikroracunalnika Galaksija.
Univerza v Ljubljani, Fakulteta za elektrotehniko, 2007.


Abstract

Due to various reasons a shortage or even absence of detailed documentation
for older microprocessor systems is common today. Because of this we often
have to resort to reverse engineering for which a knowledge of practices
and patterns used at the time of design of the system in question is of
great importance.  

Galaksija is a Yugoslavian home microcomputer from the 1980s with some
historical value. Because of publication in magazines a part of hardware
documentation and a large collection of software, including the operating
system, has been been preserved to this day. As a typical and at the same
time  relatively simple microprocessor system from that time Galaksija
offers an insight into the design practices in the 1980s.

The first part of this thesis includes the study of the preserved
schematics and reverse engineering of the software in order to construct
a complete documentation of Galaksija's hardware architecture. This
documentation is then used to design and construct a replica of Galaksija,
that is a modern electronic circuit that is software compatible
with the original microcomputer and which is capable of running the
original operating system.

Design of the replica was the basis for the second part of this thesis
which documents unusual and interesting hardware design considerations.
The working replica also served as a tool for research into original
operating system system design. The purpose of this part is to aid
any future projects for redesigning hardware from this time period.

A number of software tools were created during this work, including a Z80
disassembler and a software developers kit for Galaksija architecture.