The graphics card can act as a bus master, and grab the bus from the CPU card, with the CPU card granting access to the bus when needed.Press question mark to learn the rest of the keyboard shortcuts Log In Sign Up User account menu 58 The Weather STAR 4000.Anyone who knows or watched TWC in the 90s, likely remembers this thing.Not a traditional computer, but it does rock TWO MC68010 CPUs, which was a powerhouse for its time.
Weatherstar 4000 Emulator Software To RunAnyone who knows this particular equipment, also knows the software to run this machine was transmitted over satellite which went End of Service in the summer of 2014, Therefore ending its 24 year run. There are various other threads here on reddit, such as this one: and a few others. I always loved the STAR 4000 growing up as kid, long before I knew what it actually was, that was producing the local forecasts and warnings on cable. Weatherstar 4000 Emulator How To Get OneSo, I set myself out on a mission to figure out how to get one of these running again. Happy to report that I have gotten the machine working in a primitive state, just so happens to be the same state as the machine ran originally when it debuted between 1988-1990 or so, Just before they implemented graphics mode. My software is still very much in development and will only get better with time, hopefully achieving how it displayed before it was taken out of service. Eventually I will end up doing a full blog on this machine in time, probably on hackaday.io or some site like that. Not sure if reddit does blogs, or if anyone would be interested in this kind of thing as its in a highly niche part of the computing sector. Anyways, on to the brief nerdy stuff: (Again, will blog in full detail later) I had to fully reverse engineer the system back into a netlist, and eventually into my own version of the schematics in order to get a grasp on how the hardware works Since I am no expert at the 68K from a software standpoint, I ended up scrapping the idea of reverse engineering the existing TWC proprietary version of the old Ready Systems VRTX-32 ROMs. Weatherstar 4000 Emulator Code Sets UpAlso, the graphics card contains its very own 68K, and its ROM was setup to be a bootloader only, with a TRAP toolbox routine in the ROM which is orphaned, assuming the downloaded program code sets up the vector table with this information. So I scrapped the ROMs, and completely started over writing my own little simple bootloader and BIOS, I wrote those in Assembler, and then the main program that runs on the machine was written in C. Specs: Two Motorola 68010 CPUs. CPU card, one on the Graphics card. Graphics card has non dual port RAM for the framebuffer memory, which is interleaved with the pixel clock so its one of the caveats of the hardware making drawing slow. It is also an Indexed color system with a 256-color palette of which you must send to the RAMDAC yourself. Two Intel 8031 CPUs (MCS51 Arch), one on the graphics card which provides all the framebuffer handling code (scanline cpu). And there is one on the IO card which contains the keyboard port, LEDs, logic switches and Modem with RS232 port at 1200Baud. Communication between the 8031 and 68K on the graphics board is via FIFO. One 8044 CPU that handles the SDLC framing and decodingprocessing from the satellite baseband subcarrier, FSK-NRZI modulated. Thats a total of 5 processors Nuts isnt it I feel as if they over-engineered this thing. ![]() So I ended up writing that code myself in a hackish way to get the job done. The other hardware limitation is the Graphics board uses paged memory access to the main system bus.
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