Read Me

z81    - a ZX81 and ZX80 emulator for the Linux console
xz81   - a ZX81 and ZX80 emulator for X

Z80 emulation and much X code from `xz80', copyright (C) 1994 Ian Collier.
ZX81/ZX80 support and svgalib front-end (C) 1995-2004 Russell Marks.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


ROM issues
----------

While Amstrad allow free use (in emulators) of the Sinclair ROMs they
own the rights to, it seems they *don't* own the rights to the ZX80
and ZX81 ROMs. With the situation therefore being rather uncertain, I
can't include the ROMs. I will, however, note that they're available
from ftp://ftp.nvg.ntnu.no/pub/sinclair/roms :-), and that you require
at least the ZX81 ROM for the emulator to work.

Alternatively, if you have a real ZX81 and can use zx81get (see
below), you could use `saverom' to get a copy of its ROM; see
saverom/README.

If you put the ROM files in the directory you're installing from,
`make install' will install them for you.


Roadmap
-------

The COPYING file contains a copy of the GPL described above.

NEWS and ChangeLog describe differences between versions.

GAMENOTES contains, well, notes on certain games. :-) (For example,
how to get the commonly-distributed version of QS Defender working.)

The games-etc directory contains some old PD games I wrote for the
ZX81, and a crude sound demo.


Description
-----------

`z81' is a Sinclair ZX81 (also known as the Timex TS1000) emulator,
which can optionally emulate a ZX80. It uses svgalib. It supports most
programs and games. It supports the pseudo-hi-res mode, overscanned
modes, the ZX Printer, and both VSYNC-based and AY-3-891x-based sound.
It saves and loads programs in Xtender's .P format, but should also be
able to load .81 format files. (It works on the ones I've tried, but I
haven't tried many.)

`xz81' is a version of `z81' for X. It should work on non-Linux
systems, though it probably needs a relatively modern Unix box. xz81
should work on most displays - depths of 1/4/8/15/16/24/32-bit are
supported, though 4-bit is currently untested.

In addition to the emulators, z81 comes with `zx81get', a
(Linux-specific) program to transfer programs from ZX81 tapes using a
soundcard (or more precisely, via /dev/dsp). Loading from ZX81 tapes
is no easier than it ever was :-), but it seems to work fairly well.

Failing that, at the time of writing you can get various ZX81 programs
from:

  ftp://ftp.worldofspectrum.org/pub/sinclair/zx81

  http://www.unsatisfactory.freeserve.co.uk/zx81search/
	(largely a nicer frontend for the above)

  ftp://ftp.nvg.ntnu.no/pub/sinclair/zx81


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

You'll need an ANSI C compiler. `gcc' is fine - as should anything
else be, these days.

Check/edit the Makefile first - it should be ok as-is for Linux.

Then, on non-Linux systems, or if you only want the X version, or if
you have no idea what I'm talking about here :-), do `make xz81' then
(as root) `make install'. That should compile/install only the X
version. If you're running Linux, you should note that only compiling
the X version means zx81get isn't compiled - do `make xz81 zx81get'
(then `make install') instead if you want that too.

If you have a Linux box with svgalib installed, just do `make' then
(as root) `make install'. That should compile z81/xz81 and zx81get,
and install them in /usr/local/bin.

Once z81 is installed, don't forget to read the man page.


About the programs in the `games-etc' directory
-----------------------------------------------

A while back I wrote a few Tetris clones, one boring ordinary one, one
`hi-res' one, and a 1k version. I've bundled them with z81. See
`tetris.txt' for details. There's also mine81, a `minesweeper' clone;
see `mine81.txt' for more on that.

Having added support for AY-3-891x-based sound addons in 2.0, I
thought I might as well port a tune I wrote for the speccy (or rather,
that I ported to it - it's the ingame music from my `zblast') as a
generic AY-thingy test. :-) That's `aydemo.p'. At the moment it only
works on the Zon X.

They're all public domain (apart from the GPL'd tune in aydemo.p), so
you can do whatever you want with them. Source is in *-src*.tar.gz.

Some ZX81-related utils are included in tetris-src.tar.gz - these are
zx81send, which transfers a .P file to a real ZX81; and bin2p, which
converts a binary m/c program into a self-running .P file.


About `xz81.xpm'
----------------

This is a slightly nicer colour version of xz81's `built-in' mono
icon. If you're using xz81 and your window manager supports loading
XPMs from files to use as icons, then you might want to use it instead
of the default icon. It's installed in the same directory as other z81
data files - /usr/local/lib/z81 by default.


History etc.
------------

I decided to write a ZX81 emulator in 1995, having got a bit tired of
having to run dosemu to use Xtender 1.x, which aside from being for
DOS, and being shareware, was a good emulator. (sigh)

Thanks to the GNU GPL, I could use Ian Collier's Z80 emulator from
xz80, a ZX Spectrum emulator for X, and replace the X and Spectrum
support code with that for svgalib and the ZX81. (I wrote xz81 later.)
And I was writing this README the following evening. This is an
argument for open source. :-)

I give Ian the main author credit for z81, as the Z80 emulation is
much harder to do than emulating the ZX81's hardware and patching the
ROM for save/load etc. However, any correspondence regarding z81
should be to me, as Ian hasn't had anything else to do with it and,
being more of a speccy fan (I think), may not appreciate being hassled
by those of the ZX81 persuasion. :-)


Contacting me
-------------

You can email me at rus@svgalib.org.


Share and enjoy! 

-Rus.