Virtual Nascom

                    A Nascom II emulator/simulator

                       Version 1.9, 2009-11-21

                            by Tommy Thorn

               homepage: http://www.nascomhomepage.com
        git repository: http://repo.or.cz/w/virtual-nascom.git



This is a version 1.9 of Virtual Nascom, yet another Nascom II
emulator. There's emulation support for nearly all the standard
hardware and it runs nearly all of the software on the
nascomhomepage.com (see KNOWN ISSUES below).

Version 1.9 switches from a (partially broken) X Window specific
implementation to portable and more more robust SDL implementation. It
also gained basic serial port support in the process.


INSTALLATION

Virtual Nascom should compile on all platform with SDL support, but
has only been tested on Mac OS X 10.5.7, Mac OS X 10.6.2, and Open
SUSE 11.1/AMD64.

To compile you may have to adapt the Makefile with the libraries you
need and their path, but generally it should be enough to simply run

  $ make



USAGE

Usage: ./virtualnascom {flags} {commands}
           -i <file>       take serial port input from file (when tape led is on)
           -m <file>       use <file> as monitor (default is nassys3.nal)
           -v              verbose

VirtualNascom expects to find `nassys.nal' (unless you changed the
monitor using the `-m' option) and `basic.nal' upon startup.  You can
add files to be loaded by providing them as arguments at the end of
the line.

For example to run Pac Man, run

  $ ./virtualnascom programs/e1000/pacman.nas

and type E1000 in the Nascom II window. Control with arrow keys.


CREDITS

A very crucial part of Virtual Nascom is the excellent Z80 emulator
from Yaze, Copyright (C) 1995,1998  Frank D. Cringle.


TODO

- embed the monitor and basic images into the binary

- rpm and pkg installations

- update sdk to forgo warning on MacOS

- UI:
    allow for switching input and output file while running
    support pixel doubling

- snapshot and resume complete machine state

      vnascom -s <state>

    resumes the state in <state> and saves the new state upon exit
    (unless explicitly aborted). The previous state is renamed to
    <state>~ to keep a backup.

    UI: take snapshot, reset, abort, revert

- Precise timings

  A rough, but machine independent job should be easily done.

- Complete the keyboard emulation

  Currently we try hard to map keys to nascom keys.  This has some
  problems as shift goes to shift, e.g. when you press Shift-2 to get
  @, Nascom will actually get 'shift' '2' and make the '"'

  Doing a more standard emulation will loose the possibility of
  emulating shift keys.  Ideally, there should be an invokation flag
  to chose between the two ways of doing it as it really depends on
  the application.  Most won't need the shift event.

- Use autoconfigure

- Emulate sound

  Requires precise timings.

- Complete hardware emulation

  Check other ports that require emulation

- Internal structure

  The current organisation is a bit of a quick hack, but it works
  fairly well.

- Screen: Are Nascom characters really 16 pixels high?

KNOWN ISSUES

- Galaxy Attack doesn't work on Virtual Nascom. As it does work on
  Constantin's Nascom emulator it must be an emulation bug.