
ZX81Emu V0.5
============

These notes are very basic at the moment...


Summary of Features
-------------------

    + It does emulate a ZX81!
    + Supports use of Z80 machine code
    + Supports unimproved and improved ROMs
    + Supports the load/save of a single snapshot
    + RAM size is configurable
    + You can type in and run commands (or even programs if you have enough patience)

    - Runs very slow
    - No load/save support
    - Keyboard entry is incomplete
    - No high-res support


Zip File Contents
-----------------

    ZX81Emu05.prc   The ZX81 emulator palm executable
    ZX81ROM.pdb     The ZX81 ROMs
    1KChess.pdb     "Tape" database to load "1K Chess"
    3DMaze.pdb      "Tape" database to load "3D Maze"
    Readme.txt      This file!


Installation
------------

    NB: If you have a previous version installed, please remove this first prior to
    installation of the new version.

    You must install the first two above files for the emulator to work!

    The example "Tape" databases DO NOT WORK! They are provided to demonstrate the
    "Catalog" function within the emulator, hence the installation of these files
    is optional.

    Please note I cannot accept and responsiblilty for damage caused either directly
    or indirectly by this emulator. You paid nothing, I owe you nothing. If you don't
    accept this condition, you are not permitted to use this emulator.
    

Version History
---------------

    13-Nov-2001     V0.4    First public release. The emulator works but is very s-l-o-w.
                            Keyboard entry is not finished. Load/save not yet supported.


    11-Dec-2001     V0.5    Added support within emulator for both the "improved" and
                            "unimproved" ROMs, but still no update for keyboard entry or
                            load/save :-(


User Guide
----------

    Very breifly:
    
    You can use the snapshot facility to save the current state of the emulator so as it
    can be quickly reloaded at a later time. The snapshot load/save can be manually
    actioned (from items within the FILE menu) or automatically action at emulator
    startup/shutdown (by configuring the options under the SETUP menu).
    
    Key input can be achieved through graffiti input or by tapping on the screen to
    reveal the ZX81 keyboard (recommended, as the graffitti input routine is still
    work-in-progress and will "hang" until the screen is tapped!). When pressing keys,
    keep the key down for a while, so as the slow emulator has a chance to see it
    as "pressed". Have a play...


To Do
-----

    Things that will happen "soon":

        * Complete DBConvert (eg add printing support and WAV import/export) 
        * Better Documentation! 
        * Complete Load/Save routines. 
        * Complete keyboard entry routines 
        * Faster emulation (optimise Z80 core, faster screen updates, patched ROMs) 

    Things that might happen later:

        * Add support for LOAD "" command 
        * Implement the OS find facility 
        * Saving of BMPs 
        * ZX80 ROM Support 
        * Support for more than 16K RAM 
        * Slower emulation (might need to throttle back on faster Palms!) 
        * Release of the source code, once it is more stable and tidy 

    Thing that will never happen (just don't ask):

        * Spectrum Emulation - It would be too difficult for me to do 
        * Hi-res support - Just not an option with Palm's 160x160 display 
        * Colour support!


Special Thanks
--------------

    Thanks to Marat Fayzullin for his portable Z80 emulator. Excellent work. I have modified
    the Z80 core slightly so as to fit into the segmented architeture of the compiler.


Copyright
---------

    Contents are copyright Mr. Stephen Agate, BSc (Hons.)
    This zip file is freely copyable. Enjoy.

    More info & updates can be found at http://www.agate.f9.co.uk
    Email: zx81@agate.f9.co.uk
