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Omega-TI

Is an FPGA FDC possible (while not being practical to make).

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Just out of curiosity, I was wondering if an FPGA based floppy drive controller is a possibility. It would probably not be practical to make of course for the smaller quantities that would be sold, but with a TI that has 32K built-in, having a Lotharek HxC in a little case like this with it's own controller would sure be cool.

 

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It's not only possible, it's very practical. FPGA's are perfect for a small batch where you don't want to wire together a mountain of discrete logic, and you don't have the funds to roll an ASIC chip. Grab yourself a cheap FPGA dev board and try it out!

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Thanks Greg,

 

Unfortunately that's currently above my knowledge level, but it's great to know. I have no immediate need for one myself, but if one ever became available I'd probably pop for it.

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My understanding is in order to read a DVD or CD you need over 1 meg of RAM and the TI does not have a big enough buffer.

 

It would require a 9938 or 9958 with more VDP RAM for Buffer like the Geneva and much more RAM like the SAMS 1 Meg Card.

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????? You lost me Rich, we were talking FPGA floppy controller that would fit into the case with an HxC. It would be a nice & tidy expansion for people running 32k internally.

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FPGA are not programmed in the way we write our C programs, but still, MESS should be a good source of information if someone really decides to create such an FPGA emulation. We implemented the controller chips according to the specification documents, including all the state machines, as far as they were publicly described. It is not really difficult; I'd expect it's just at the skill level of a video controller. The HFDC chip (HDC9234) needs a 10 MHz clock, the FD1771 uses 2 MHz, WD177x require 8 MHz (for the internal data separator).

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