Free simulator software for linux

MOS 6502 Simulator is sort of an emulator for a 6502 chip. Theres virtually nothing apart from the CPU (minus BCD operations). It also bears no heed to instruction timings.

Whilst (apart from those two things) it successfully simulates the CPU there were a few design flaws, which led me not to continue with it:

- I wrote it in C++.

As the 6502 had no dedicated IO bus, everything was done via memory. I had the idea of having a pure virtual class which provided a generic interface, then as I wrote devices to sit in the memory space, they could just override portions of it, or trap on writes or something.

Whilst writing this, I kept getting the feeling I should have written it in asm instead Especially for manipulating flags and rotates and stuff. (as I could have just rotated AL, for example, rather than the mess I have in the C++ code.

- Sloppy instruction decoding.

I originally set out to decode the instructions properly, but there were lots of exceptions to the system used (esp. if I intended to support the 65C02 for example). This decended into a massive switch statement. I almost considered splitting it up to smaller files, and just #include them in the middle, just to make it more managable.

Also, as they are not in numerical order (grouped according to type, or addressing mode, cant remember atm) it wouldnt compile to a jump table. Does with optimisation on though.

The main thing that prompted me to write this was I found my BBC-B in the loft, and felt a pang of nostalgia for the hours wasted hunched over it in the lowest resolution text mode (IIRC mode 7 to save ram). I had the idea of writing a NES or BBC emulator, however it didnt get that far.

It has a pretty simple image format. The file must be >= 65536 bytes (64k) and that is simply the memory image for the system (16-bit address bus). There is a strange sort of ASCII text display at 0x200, which is ok enough for spewing a string to. As it was just thrown together in the space of 6 hours or so (took a long time to do the switch statement) its not very thouroughly documented, but hey.

GNUSim8085 is a graphical simulator for the Intel 8085 microprocessor.
GNUSim8085 is a simulator and assembler for the Intel 8085 Microprocessor, in GNOME environment.
GNU 8085 Simulator contains an inline assembler and a debugger.
Enhancements:
- New: Use gtksourceview as editor component.
- Fix: Syntax highlighting working again.
- Fix: About dialog does not close by pressing close button.

GTP server simulator is a simple responder for the GTP (GTP prime) protocol that works with the Cisco Content Services Gateway to provide per-user traffic limits.

GTP` (GTP prime) server simulator (it permits any content and provide quadrants for every operation) binaries for Linux (run under Fedora Core 4 and 5).

The binary was tested with Cisco CSG.

PHP Keno Simulator project is a Keno payout ruleset simulator.

PHP Keno Simulator is a payout ruleset simulator for the classic game Keno.

You can tune the payout chart to fulfill your "house advantage" or you can just calculate for fun (predefining the correct payouts) what the odds of winning are and how much your local casino is making for its owners.

Hardware::Simulator is a Perl extension for Perl Hardware Descriptor Language.

SYNOPSIS

use Hardware::Simulator;

# NewSignal( perl_variable [, initial_value]);
# create a signal called $in_clk, give it an initial value of 1
NewSignal(my $in_clk,1);

# Repeater ( time_units , code_ref)
# every time_units, call the code reference, starting at the current time
Repeater ( 5, sub{if ( $in_clk==0) { $in_clk=1;} else { $in_clk=0;}});

# Responder ( [signal_name ... signal_name], code_ref );
# respond to any changes to signals by calling code reference.
# any time out_clk changes, print value of clock and simulation time.
Responder ( $out_clk, sub
{
my $time = SimTime();
print "out_clk = $out_clk. time=$timen";
});

# start processing of events and event scheduling.
EventLoop();

Hardware::Simulator ==> a Perl Hardware Descriptor Language

Hardware::Simulator is a lightweight version of VHDL or Verilog HDL. All of these languages were developed as means to describe hardware.

Hardware::Simulator was created as a means to quickly prototype a basic hardware design and simulate it. VHDL and Verilog are both restrictive in their own ways. Hardware::Simulator was created to quickly put something together as a "proof of concept", to show that a design concept would work or not. and then the design could be translated to VHDL or Verilog.

The problem that started all of this was designing a fifo for a video scaling asic. The chip used a buffer to store incoming video data. The asic read the buffer to generate the outgoing video image. We estimated how large we thought the buffer needed to be, but we wanted to confirm that our numbers were right by running simulations.

The problem was we needed to run hundreds of different simulations, given the permutations of input image formats, output image formats, and input/output clock frequencies. We also had text files containing valid formats and frequencies. A text file as input called for perl to manipulate, split, format, and extract the data properly.

This data then had to be translated onto the a HDL simulation. The problem was that there was no easy way to write a perl script that would simulate hardware, so the only solution was to have perl drive a Verilog simulator and pass all these parameters via command line parameters. so then verilog files had to be created, and the simulator had to be driven, and the end result was a lot of work to simulate a simple fifo.

Time contraints did not allow me to develop a HDL package for perl to solve the original problem, but I took it on in my spare time. and eventually Hardware::Simulator was born.

The SigmaPi Neural Network Simulator is designed for time-series processing and neural network research on Unix/X11. Since version 0.5, it uses the LSTM neuron model, the RTRL training algorithm and a heuristic learning rate adaptation based on local update sign-changes. It is GPL-covered, so you can use it for free (read the license for more information)

The current version runs with the Trolltech QT 3.x API and is therefore platform-independent.

SigmaPi is no end-user software. It allows the user to change every possible network parameter, and it wont tell you whether a setting is nonsense or not.

Elfelli is a tool to simulate and visualize electric flux lines around arbitrary positioned, electrically charged bodies.
The project is able to export PNG files of the current canvas. Elfelli is written in C++ and uses gtkmm.
Compiling:
To compile Elfelli, you need SCons. In many distributions you will also need the development package of gtkmm (in Debian this is libgtkmm-2.4-dev).
Compiling itself is very simple:
$ scons
Installation:
To install Elfelli, simply type:
$ scons install
By default, it is installed in /usr/local. If you want to change that prefix, alter the install command to:
$ scons install prefix=/install/prefix
Enhancements:
- Its now possible to save and load the current scene as well as changing a bodys charge.

Vamos Automotive Simulator project, as the name suggest is an automotive simulation framework with an emphasis on thorough physical modeling and good C++ design. Vamos includes a real-time, first-person, 3D driving application.

Vamos is young and its goals are only partially met. I invite anyone whos interested to contribute.

Thorough physical modeling

Vamos models most major systems of a car. The drivetrain includes a simulation of the engine, clutch, transmission and a limited-slip differential. Tires and suspension are also modeled. If I missed something, let me know.

Good C++ Design

The geometry, track, car and world modules are in their own namespaces. Care has been taken to avoid cyclic dependencies. Standard Library components like strings, vectors and maps are favored over arrays. Some of the modules and classes have aged more gracefully than others. If you see a design area that needs improvement, feel free to pitch in.