V9t9 emulates the TI-99/4A (by default) though it can support other
machines -- only made-up ones for now, using much of the same hardware.

I've been working on this in various forms since 1992.  The Java port
was quite nastily ported directly from the C port starting 2005.  The C
port never really saw the light of day (it was a bit way too geeky for
the average user to understand, and only built against GNU C in Linux
and Metrowerks Codewarrior in Windows).  The C port was written from 
the assembly port which formed the original V9t9, back when it was 
still being sold.

To build standalone, see v9t9/v9t9-java/Deploying.rtf.
This will make a standalone Java application launchable through a script.

To build and develop in Eclipse, which is easier but requires Eclipse 3.6
(not tested on anything newer), import base/ejs-base and v9t9/v9t9-java/*.
Afterwards, go to Window > Preferences > Java > Build Path > User Libraries
and define a library called SWT which points to an SWT .jar file from
base/ejs-base/libs/swt (e.g. org.eclipse.swt.win32.win32.x86.jar).  
At this point everything should build properly.  Then run v9t9.gui.Emulator.

-- Ed