RISC OS build of AmlieEm - v0.01an (2008/03/12)
================================================

This build of AmlieEm has been put together to
allow those using RISC OS to see the emulator in
action.

Please read the "Licence" file.


This version was built under RedSquirrel on my
PC (a 450MHZ Pentium III jobbie). This is the
second version to be built under emulation.


The display mode used is MODE 46 on older machines,
and a 640x200 mode on RiscPC style machines. An MDF
is supplied to set up a 90Hz refresh mode; though
if this is not available then it will try to use
the built-in 640x200 mode. And if THIS is not
available, it will revert to MODE 46 (yuck!)

MODE 46 provides a basic 16 colour screen with the
same sort of dimensions as a "CO80" display under
DOS. However it will appear 'letterboxed' on many
systems (i.e. any multisync/SVGA type).

The 640x200 mode is much the same, but it will be
a smallish correct-aspect (non-letterboxed) display
in the centre of the screen. This is, frankly, a
whole lot better than using a letterboxed mode!


The display and colours are set up by the BASIC
program "SetPalette" before the main executable is
run - so if you wish to twiddle the colours...
The colours are now set up in accordance with a
peek at those colours generated by "!PC" when an
image of a DOS display is saved as a sprite, so
now the colours will look correct.


The EPROM image is called "EPROMimage", the quick
load/save file is called "QuickSave". Both of these
reside within AmlieEm's directory.
Other file operations (save/load ram, etc) also
point to within AmlieEm's directory.

NOTE, however, that due to differences in the size
of an "integer" between RISC OS and MS-DOS, not to
mention the word order, the quick save files are
NOT considered compatible, so they have different
marker IDs (DOS=2, RISCOS=254).
Twiddle this in !Zap at your own risk...


The emulation is NOT quick. It does not manage a
full-speed emulation of a 2MHz 6502 on a 450MHz
x86 processor (and it runs at 0.02% under an
Acorn RISC emulation on said machine).
This software is designed to be simple to
understand and simple to implement. There are many
faster methods to emulation, however the trickier
the code, the trickier it is to understand. Ever
tried to figure out how a JIT worked? :-) This is
not the case with AmlieEm. Instead, the aim is to
make an emulation that is reasonably faithful to
the hardware, while being simple in design and
implementation. It is hoped that the code will be
largely self-documenting.


Everything else should be as described in the
documentation for the DOS release.


Rick Murray
2008/06/17
