OZ v5 - The steps for rebuilding the Z88 operating system


OZ is certainly the best multitasking operating system working on a 8 bits computer. Paul Bond was the main programmer who designed and programmed it.
Since its start, he designed a very interesting boot option. On reset, if there is a special pattern in slot 1, OZ jumps to it. Paul Bond thought probably that one day, there will be flash eprom cards which could contain OZ in slot 1.

  1. OZ on a 1M Flash Card in slot 1

    2. A large 1MEG card for OZ, applications and system files would be enough. Every one could download the latest OZ from internet, upgrade the Z88 like flashing a BIOS on a PC. This could be done by a simple BASIC flashing 64K or 128K images, depending on free RAM.

  2. The first step : Getting the OZ v4.0.1 sources

    3. Firstly we need the sources... We are still waiting for them. I've disassembled a major part of them, understood and localised the big parts, it is an exit if we never got them. Then, translating them to the excellent Z80ASM format, for the start we only have to do it for 64K of code :

    Actually all disassembled, 50% remarked...the aim is to recompile it and get the same image as v4.0.1. The sources have to be sure, no bug adding. 'If necessary, the developers package can be extended to support features maybe necessary to build a large ROM, an not only a single module oriented application.' wrote Gunther. Actually the assembler seems to support all the required options.

  3. Step two : OZ v4.1, slot one and major bug fixing

    4. All the sources are rewritten to support the slot one basis. It is the major work. I'm very afraid with the interruptions, especially with the OS_OFF and the NMI (non_maskable interrupt), because the COM blink register was designed to switch the low $20(RAM) or $00(ROM) banks but never the $40(slot 1 first bank). The major bugs are fixed during this stage too. When done, this will be the OZ v4.1 (UK version) for slot 1. Here is the major bug list :

  4. Step three : OZ v5

    5. This stage is very far, hoping it will exist one day... These improvments are classified by categories here.

  5. The Project

    6. This OZ v5 project is one of my old dreams. It is probably the same as all the Z88 enthousiasts. It represents a lot of work, I'm not a good programmer and wouldn't have enough time to do that. This project could be the future of the Z88 community. I will maintain this page with your ideas, point of view, disagreements... My work about the sources is available for interrested people.

    Z88 Forever!

    thierry.peycru@libertysurf.fr

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