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About Xenophon

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    Space Invader
  1. I suppose the easiest design would be A Z80 CPU (Z84C00xx) CMOS Z80 74LS138 or 74HC138 Memory decoder 6264 (8K SRAM) x 3 AY3812 Sound Chip (I/O decoded using a GAL) al this would plug into the Z80 socket, though the original Z80 CPU would need to be replaced first. The beauty of this design is that it fits inside the CV's Case and doesn't need to be connected via the expansion socket. Though some soldering work would need to be done. Any ideas or suggestions are welcome !
  2. As this idea is still on the drawing board and Since I'd be using as GAL or CPLD any available port could be used ! Could even include an RTC , CTC, and even a Maths Co-Processor !
  3. Hi. I was toying with the idea of design/building an Accelerator board to fit inside the CV . something quite simple but powerful enough to be useful. It would plug directly into the existing Z80 footprint. Plugs into Z80 socket on CV board. has Z84C0008PEC 8MHz (switchable between 3.58 and 716MHz) 24K SRAM 3 pieces 6264 SRAMs 8K EPROM ( uses original CV ROM) Memory decoding done using 74HC138 GAL used to switch between Standard 3.58MHz and Turbo 7.16MHz mode when hFF I/O is written to ? The PCB would be quite small and inexpensive... Any ideas or suggestions are welcome !
  4. What type of hardware are you thinking of building ?
  5. Hi. I'm looking to making some bare Colecovision Cartridge PCBs does anyone have any schematics or a link to some. I was thinking of making a batch of bare PCBs & sell any surplus at cost and make some plastic cases using a 3D printer so they'd look just like the original ones.
  6. V9990 schematics : https://www.ist-schlau.de/hardware.html
  7. The Kiwi 68K project uses a V9990 ...schematic etc at : https://www.ist-schlau.de/hardware.html
  8. It is possible to have a larger long term project like those mentioned above and several smaller 'Quarterly' project running simultaneously by various people / groups ?
  9. The Obvious PROJECT is build a completely NEW TI-99/4A .. the way it should of been built .. with more RAM , better graphics etc , yet still 100% backwards compatible. TMS9900 CPU (as in original) TIM9904A TMS9901s TMS9902s to give serial I/O MORE RAM MORE ROM possibly even using a 74LS612 Memory Mapper? Cartridge Slot as in original V9958 video with 192K VRAM SN76489 PSG YMZ284 (AY-3-8910) Sound Chip Real Time Clock Maths FPU (AM9511 or similar) to speed up maths functions 8255 PIO for internal PATA IDE (CF card or Hard-Drive) etc etc Have a Turbo Mode where the TMS9900 is clocked at 16MHz(4MHz internall) , done by software.
  10. Perhaps just start with a simple homebrew design as a starting point, something like: Z80 CPU Cartridge Slot (32K Cart as original) 8K SRAM 8K SRAM 8K SRAM 8K EPROM 74HC138 + 74HC139 Memory decoders, (24K SRAM + 8K OS ROM) V9958 Video board with sound Possibly Four expansion slots for add-ons and prototyping new hardware. The controller circuitry and stuff for 'Joypads' etc could be copied from the original CV ? I've already seen several working V9958 schematics and at least one V9958 VDP board so quite a bit of the work has already been done. This type of thing could be done as a hobby with little to no funding.
  11. It's about time some NEW Colecovision Hardware came out , just to keep the system alive and kicking.
  12. Hi. Does anyone know where to get (downloadable) hardware/service manuals for the Colecovision ?Stuff with full technical details of the Coleco ??
  13. My draft design (to breadboard) would be : Z80 CPU (possibly Z84C0006PEC or Z84C0008PEC) as these are very cheap: http://www.ebay.com/itm/10PCS-Z84C0006PEC-Z80-CPU-Encapsulation-DIP-/371218968377?pt=LH_DefaultDomain_0&hash=item566e5fef39 http://www.ebay.com/itm/10pcs-Z84C0008PEC-Z84C0008-DIP-40-/171399504172?hash=item27e834e12c SRAM (static RAM) as opposed to the original DRAMs .. probably use 64K to allow CP/M option ?? EPROM 27C64 for O/S etc ? V99x8 Video (seen several schematics of boards already done) making this somewhat easier SN76489 Sound Chip YMZ284 / AY-3-8910 Sound chip for MSX sound Glue logic / could be TTL /PLD/GAL or a CPLD yet to decide Shall start breadboarding as soon as stuff arrives, all going well !
  14. I've been pondering for some time about building my own Super Colecovision console/computer and now I feel iit's the time to strike ! So I've bought some breadboard, wire, already had tools soldering iron etc and am now doing a draft design and looking at what components ICs I'll need. OK my knowledge of microcomputers and electronics isn't great, but that's the whole point I'll be on a steep learning curve and even if I don't make a working Colecovision (which is most likely) at least I tried and learnt stuff on the way ! Is anyone else doing a similar sort of thing >?
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