Crosstalk

The mission statement of Crosstalk is that we would like it to bring back the joy of tinkering, designing things from near-scratch, and taking one's time with something, all while letting people connect and collaborate. We don't see that much anymore in computing. Crosstalk , noun, engineering " Crosstalk between signal channels denotes the interactive influence between two independent channels as a result of leakage currents and capacitive or inductive coupling. Crosstalk between the channels changes the signal by the value of the amplitude of the crosstalk signal. " - Siemens: SIMATIC ET 200AL Manual Collection Crosstalk is a printed circuit board builder and simulator that functions as a sandbox for building electronics. Players can construct and program devices ranging from calculators to complex computers. It comes with a gate-level SystemVerilog simulator that consists of an elaborator, a synthesizer, and a C emitter, plus the Clang compiler, which compiles the emitted C code and runs it for faster design execution. The C code is derived from players' own SystemVerilog. The default workflow is wiring a schematic, routing a PCB, describing a processor core in SystemVerilog, programming it, and then writing software for it. The game supports a networked mode, in which one collaborates with other players. Designs (cores, software, custom ICs, component libraries) can all be shared via the Workshop. Serial interface Crosstalk can interface with devices using virtual in-game serial ports or the running machine's physical serial interface, which is /dev/ttyUSB<n> and /dev/ttyACM<n> on Unix and COM<n> on Windows. External devices can thus be plugged directly into designs and be represented by stand-in parts. Players could use microcontrollers, sensors, physical buttons, or even other computers. The supplied terminal emulator can be used as a serial terminal I/O device. Scopes Memory view of the running design and an oscilloscope are necessary tools while building, so they're both included and easily accessible to players. Memory view and runtime activity indication An oscilloscope attached to a signal, like sound output Display output If a design has a video display output, then players can use one of the three built-in display modes: CRT, gas-plasma, and modern LCD. The concrete interfaces used are CGA (for CRT and gas-plasma) and VGA. A CGA gas-plasma display output type showing the DANGLING kernel booting on an i386-compatible CPU, in-game The in-game displays are interactive Designs built in Crosstalk represent structurally valid PCBs, which, combined with Crosstalk's physical simulation, means that there's an educational element to playing. It also means, with the exception defined in the "IC design" section, that electronics designed in Crosstalk can be fabricated using standard and widely available PCB fabrication and assembly services, and as such, brought into the real world. One could design a fully functional microcontroller board in Crosstalk and have it fabricated and assembled using a PCBA service without additional setup or utilities. One would take the Gerber, drill, and pick-and-place files and the bill of materials from the export and send these directly to a PCBA service. IC design Crosstalk is capable of generating symbols, footprints, and STEP models from parameters supplied by players. With this in hand, a player could design a custom integrated circuit, program it, and make it part of a design. In order for custom IC design to be available, players need to disable fabrication mode in the settings, which disables manufacturability checking and related features. When it comes to the contents of a custom IC, one can choose whether to define it electrically, logically, or both. An IC could be an electronic circuit enclosed in a package and reused en masse, but it can also be a processor. If one chooses specifically the logic path, then the electrical properties of the IC are derived automatically, but may be modified. If an IC is defined electrically, then there is no (boolean) logic to speak of. SystemVerilog FPGA designs can be described using vendor-neutral SystemVerilog. SystemVerilog can also be used to describe the logic of custom ICs. For accelerated execution, there is a built-in option to emit C99 from the supplied SystemVerilog using Crosstalk's toolchain and the enclosed Clang compiler. If this option is not enabled, then the design will be simulated directly, which takes longer. Theory The game comes with a professional component library that consists of 70 hand-picked components and their metadata. What happens in and around the PCB is computed using Maxwell's equations, heat radiation, conduction, and convection, and many other principles. Many of these principles' standard methods of solving are integrated via an in-house finite-difference time-domain physics solver (for electromagnetics) and finite-volume/explicit forward Euler over a 6-neighbor face-flux stencil/discrete-ordinates radiative transfer equation/Newton cooling (thermodynamics), based on approximately 2700 A4 pages of theory. Sandbox mode Self-play submode Sandbox mode is the default Crosstalk experience. One chooses a PCB size, difficulty (which scales starting funds and the degree to which the physics simulation is unrelenting), and starts building. Under the "Easy" and "Medium" difficulty settings, pin attribution will not be enforced, so as long as components are powered and interconnected based on their roles, they will be able to operate. If a player chooses the "Hard" difficulty, the player will have to use specific pins for specific things, such as wiring power in via VIN, outputting it via VCC, grounding via GND and COM, looping back voltage feedback via FB, and so on. There also is a detailed rule editor, which can be used to select what rules are enforced and to what extent. Networked submode In this submode, one can team up with others over Steam Networking and build together. It is structurally identical to Self-play mode, but with networking enabled. With larger designs, managing nature, the physics of electromagnetism and electricity, becomes complex, so players will need all the additional help that they can get. One can be joined by up to two other players.