7 hours ago, x16tial said:
X16 runs at 8Mhz -- 12 Mhz is better
X16 has a TON more RAM -- this doesn't matter with fast SD speeds, that same 8k can be swapped from SDCard rather than switching banks
X16 has twice the video RAM -- this might be the worst part, it means only 1bpp for 640x480, but tricks with sprites, charsets, etc would probably compensate
X16 has 4 expansion slots - provide an i/o bus on the X8?
X16 has a Yamaha sound chip - add on expansion with said i/o bus?
X16 has an IEC disk drive port - this is really kinda silly. nice nostalgia, but let's be real, who is going to use this?
X16 is infinitely more "hackable" - make the X8 more hackable, provide that i/o bus. and how about tools to make reprogramming the fpga easy?
X16 has SNES ports - not needed with the usb port
X16 has PS/2 - usb is better
As attached as we all are to the X16, the X8 is just the better idea. Even the name X16 is a holdover from when the 65C816 was going to be its processor, I believe.
In my opinion we should all bite the bullet, and go with the X8 as the platform.
Releasing both I think is a mistake.
@The 8-Bit Guy, you do this full time, so developing for multiple platforms seems like no big deal. Most of the rest of us don't have that luxury.
If there was an adult in the room, she would tell you that you are assuming that is is possible to get something for nothing.
Remember, the X8 is the "proof of concept" answer to the question, how MUCH of the CX16 design could you fit into the same FPGA that the CX16 uses for its Vera Video/Audio/SPI chip.
The answer was useful for giving an idea whether the CX16e could work with only one SRAM chip ... and also to give an idea how much more powerful of an FPGA would be needed for the CX16e.
But above, what you are talking about IS the X16e, not the LX8, and there is a
reason David estimates the CX16e would cost twice as much to bring to market as the LX8.
The LX8 is a proof of concept of putting as much as possible into an FPGA-only system, and only using the internal RAM works for the
LX8 precisely because it allows it to avoid bringing out the system bus. So "provide an io bus to the X8" means, "build a CX16e rather than an LX8" So "add on expansion with said I/O bus" means "build a CX16e rather than an LX8" So "make the X8 more hackable, provide that I/O bus" means "build a CX16e rather than an LX8" We
know that the Vera FPGA is pin constrained, because lack of pins was cited as the reason for dropping the serial port function when the register addressing was increased from 8 addressable registers to 32 addressable registers ... which is, after all,
exactly two more pins.
So there is no way they can add USB and add 16-18 pins for the I/O bus (16 if an external decoder is used for the five slot selects, 18 is each slot select gets its own pin).
The two reasons a CX16e would be about twice the cost of an
LX8 are that it would involve a surface mount RAM, because you can't GET that much RAM as an embedded FPGA module, and that it would involve a more powerful FPGA, with more logic cores and more pins, because the FPGA they are using for the Vera just doesn't have either the logic cores or the pins to handle full simulation of the CX16p ... and that more powerful FPGA would cost more money.
So the LX8 as you are imagining
it is not the same LX8 that is basically available to bring to market now, unless they decide to do a few tweaks to it.