[Coco] Super IDE vs. Drive Pak

[John Kent]

Hi Mark,

I did buy a SD-> IDE interface adapter, but it turned out to use a 5V 
flash ROM. 5V would be fine for the CoCo but you really need a 3.3V 
interface for use with an FPGA. The spec sheet for the controller on the 
adapter seemed to indicate it could run off 5v down to 3.3V. It would be 
a matter of unsoldering the 5V volt flash ROM, reading it and putting 
the code in a pin compatible 3.3V Flash ROM. The flash ROM was something 
like a 29010 and it was in a 32 pin (?) PLCC package and was soldered 
directly to the board rather than being socketed which would have made 
it easier to replace. I would imagine that the 3.3V flash ROM would have 
a different programming algorithm, so you'd have to be sure that the 
controller software didn't re-write any flash sectors for any reason.

The XESS XuLA FPGA board  has a PIC 18F14K50 micro with a miniature USB 
connector on it that allows the FPGA bit map to be downloaded via USB. I 
would imagine Microchip had some sort of software development package 
for writing drivers for the USB connection on the PC. You would also 
need some sort of USB protocol stack for the Microchip PIC chip.

http://xess.com/prods/prod048.php

John.

On 17/11/2011 2:56 PM, Mark McDougall wrote:
> On 17/11/2011 1:58 PM, John Kent wrote:
>
>> 2003/2004 was about the time I was using CF cards with my FPGA 6809 
>> system.
>> The IDE interface is much easier to understand than SD & SDHC.
>
> Has anyone looked to see if there are IDE/CF<->SD adapters available?
>
> I'm using an SD card in my "Coco with S-IDE". I use quotes, because 
> it's all in an FPGA, running stock HDB-DOS. I've wrapped a proprietary 
> IDE<->SD converter layer around the standard Opencores IDE controller 
> core, so the 'S-IDE' thinks it's talking to a CF.
>
> Unfortunately, atm, the IDE<->SD converter is read-only; that is, it 
> only supports reading the SD card. But there's not a lot to it, and 
> I'm wondering if you could do a small board with a CPLD in it that 
> does the same for a real CF<->CF adapter?
>
> Then again, not really sure why people are so hell-bent on SD vs CF?!? 
> For all practical purposes, isn't the only difference that you're 
> sticking one in the CF slot of your mutli-card reader, and the other 
> in the SD/MMC slot?
>
> Having said that, USB would be nice. But now you're looking at a USB 
> host-enabled micro, emulating an IDE device (which is very doable BTW).
>
> Regards,
>

-- 
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