CPU softcores out there which / are original designs optimized for synthesis on FGPAs in the least gate-space.

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Hah, speaking of bigmessofwires: TinyCPU. There's even a readymade PCB for it, though it should also be easily fitted into your existing device.

There's another one I can't recall right now which is loosely based on one of the ARM ISAs. And ARM have an official softcore too, though Zeus only knows what the licensing situation is with that.

/ETA/ Here's one: http://www.actel.com/products/mpu/coremp7/default.aspx#software

/ETA/ And another: http://embdev.net/articles/ZPU:_Softcore_implementation_on_a_Spartan-3_FPGA - which also implements the open-source Wishbone expansion bus. Maybe a hardware implementation of Wishbone fits in with your plans, Grackle?

But again, blawblawblaw.

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I look forward to your coredumps, myself, Gorgonops. You have a knack for explaining hellishly tricky low-level stuff in a clear and understandable way.

I've been mulling over ways to substitute a quick MCU for all that timing hardware, because I badly want DMA video on *my* homebrew computer. The smallest flexible alternative is something like a 6845

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Considered an SAA5050? Or possibly more useful, its descendant:

The SAA5050 was later superseded by the SAA5243, a similar teletext video generator chip, not only a character generator but a complete stand alone video generator, controlled through I²C.

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