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Old 17 January 2008, 03:32   #54
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Originally Posted by alexh View Post
You dont need a video cable, you've got a direct link from the floppy drive to the TV via the host machine.

An ultra basic disk image stored on the flash card. A menu system that runs on host machine used to select the initial disk(s). 5 minutes to code. Cuts the BOM of the device by perhaps as much as 80%. In the case of ST/Amiga you could even have a dual format disk.
Sounds great! I look forward to seeing your added development for this feature. As the floppy emulator appears as a standard floppy drive to whatever computer it is connected to you'll need to figure out a way to be able to software eject the inserted disk, then select the image you want from the SD and insert it (the same way as if you had a physical floppy disk with a floppy carousel controller - but it's only controlled through standard signals to the floppy I/O).

At least on the Amiga you could do something like tell the MCU if it sees a specific sequence of I/O commands on the floppy port to perform the eject / select / load functions - but that's not a lot of use if you wanted to use the floppy emulator on your CPC, Amstrad, Korg etc. which doesn't have as software controllable floppy interface as the Amiga.

Originally Posted by alexh View Post
Floppy disk drives usually have only one button (eject). They should have looked into using just one button. Then, when it came to integrating it inside a computer, there would be no extra buttons required, just hijack the eject button.

And they made something slightly more complicated than it needed to be and not cheap.
I guess you could have some extra circuitry so that when you press the floppy eject button it works similar to an action replay, so that it pauses the CPU, passes control to a small ROM which has the code to directly talk to the MCU and eject the current floppy image, list all images on the SD, load the new selected image, notifiy a disk change on the floppy I/O port and then release control back to the host machine. It won't be a generic floppy emulator any more though.

AlexH I can see where you're coming from, but this is a hobbyist project in prototype stage, NOT a commercial project and is aimed to work with ALL computers that used a fairly standard floppy drive. Prototypes usually have extra debug ports or other features which help with debugging and development, which can be omitted from the 'final' PCB design. Think of the pics of the system they have developed as being the equivalent of a Spartan3 (or other FPGA) debug board. Look at the early design of the miniMig on the Spartan3E board, then compare it to the final minimig PCB which was released.
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