QL-SD card requirements....

[prime]

Hi all,

Looking at the QL-SD source i can see nothing obvious that it is doing that requires the card to be SDHC, but I guess there must be a reason why this is so. The QL-SD code specifically checks for an HC type card and rejects any that are not.

Seems a waste to have an 8GB card with a 128MB QL filesystem on it.....

Cheers.

Phill.

[vanhauen]

Agreed...but then again, you can pick up an 8gb card on Amazon for less than a fiver and that's including postage ☺
http://www.amazon.co.uk/gp/offer-listin ... dition=new

[prime]

Agreed...but then again, you can pick up an 8gb card on Amazon for less than a fiver and that's including postage ☺
http://www.amazon.co.uk/gp/offer-listin ... dition=new

Indeed

I just wondered if there was a technical reason like you can do faster SPI to an SDHC card. This hasn't been a problem with the 8 bit SD interfaces I've seen (ZXpand, AtoMMC etc), but may be a problem when your SPI clock is 25MHz, as it is in SPI_MODE 1

Cheers.

Phill.

[Paul]

Afaik sd does not support the addressing style used in the bdi driver. Therefor sdhc is needed.
Without knowing any details. Just what I understood from what I heard.
Kind regards
Paul

[Peter]

The whole point in requiring SDHC is that I did not want to detect and distiguish card types at runtime. Which would make the code less efficient, and open the door to speed/detection issues with very old cards. Basically, it's trivial to support SD. I used SD when I started, but I didn't not want to waste boot speed and extra code to deal with both types.

And anyway I see no point in supporting SD. The cards are almost obsolete, and already more expensive than SDHC. For example, a new 2 GB SD card is €11, while 4 GB SDHC card is €4 and 8 GB SDHC is €4.50.

So I switched completely, making things easier to support.