1 hour ago, paulscottrobson said:
If the X8 can be produced at the sort of cost mentioned, which I can certainly think it might be, given the cost of similar devices, then it's almost beer money (well, a good night anyway ...). I think most people who wanted an X16 may well buy an X8 as well. I'm not sure it works the other way round.
I think code is fairly portable between the two designs, especially if you design it with that in mind. The problem is the window design is capable of doing things that the pipe design isn't, if you wanted to do a vector game the frame rate would go up significantly.
But then the X8 could be the game machine version and the X16 the experimenters machine version, you could make the Kernel calls compatible and even provide alternate kernal versions to load VRAM, position Sprites and so on. (Though if you add SPI then you can pretty much connect anything you like anyway)
I think cost is important, always have. Some of the designs out there ; the Mega65 and the various Foenixes (?) -ii (?) look excellent machines but it's an awful lot of money for a machine without a software base. Even if X# never gets a significant software base (and I think both would get a reasonable one, though it's never going to match C64 levels obviously ...) it's not a big loss. WCS scenario for me for an X8 is that I can repurpose it as something else ?
Actually, I don't think the window design is that much of a difference, performance wise. I did the math a while back and demonstrated that a pipe approach is actually faster for most approaches than direct writes.
Yes, even for vector graphics.
That's because you still have to store the address being written to somewhere, and that somewhere can be the VERA address register just as easily as it can be a memory cell. Also, as the window approach only works for 256 bytes at a time, it's actually still going to require relocating the window for writes to different lines, which isn't really any faster than writing a new address to the VERA address register.
And yes, cost is important... the $100-ish option will absolutely outsell a $400-500 option - especially if the more expensive system requires extensive soldering.