So. Remember that old project I made like one or two posts about? The Neutron retro microcomputer? Yeah, it’s not exactly a microcomputer anymore. I have changed my end goal. Now I want to make a 16-bit game console, something similar to a Super Nintendo or a Sega Genesis, but not compatible with either. What does this mean?
- The Neutron will still be using a W65C816S microprocessor, now with a target clock frequency of 8 MHz instead of the full 14 MHz.
- There will be one FPGA to handle both audio and video output.
- There will be one chip, either an FPGA or CPLD, to handle de-multiplexing the processor’s address and data lines (because Western Design Center thought making the data bus act as the most significant byte of the address bus sometimes was a good idea, even though it really isn’t and just complicates things).
- System RAM and Video RAM will be separated. Amounts are currently unknown.
- There will be at least one slot for an SD card, so you don’t have to deal with battery-backed Save RAM in the cartridges.
- There will be 4 controller ports. It is currently unknown what the controller ports will be, or what inputs the controllers will have.
- There will need to be a cartridge slot mapped to one half of the memory map (8 MB).
- Half of cartridge space (4 MB) will be banked using the same method (or a similar method) as used in the 8-Bit Guy’s Commander X16 project, for a total of 4 MB * 256 Banks = 1 GB in that one area. The other 4 MB area is static.
- There will be a parallel expansion port, because who knows what people will want to make.
- Audio/Video output is indeterminate at this stage. I’m hoping for something capable of both digital and analog output. Perhaps something based on DVI-I Single Link, which would be capable of both VGA and HDMI compatible video out, as well as some pins for analog audio out and (maybe) composite out.
(i heard this is how to say “you’re welcome” in russian, hope that site I found was right)