Hi Fabio, I don't think the speed increase will be so dramatic. I'm going to make some guesses here. I will guess CP/M to load in about 1 second at regular speed, if I speed optimize with 8 bit counters, I can probably save 10 milliseconds, but cause hours of questions when someone with a small card can't get it to work.... I'm going to keep it 16 bit... it was just a passing question. Save that bunch of 16Mb cards... they will work nicely here. :) Regards, Josh
Date: Sat, 12 Jul 2014 16:14:00 +0200 Subject: RE: [N8VEM-S100:4527] Re: A/I 8080 CPU -FAT From: hkzl...@gmail.com To: n8vem...@googlegroups.com Hi Josh, I DO have a small bunch of 16Mb cards...
But recently I started seeing baskets full of 512mb (branded) SD cards going for 1€/piece at radio/electronic fairs.
If the gain in speed for 64mb upwards only is significative, it might make sense to drop smaller cards?
Fabio
On Jul 12, 2014 4:08 PM, "Crusty OMO" < crus...@hotmail.com> wrote:
Hi Group,
A quick update, I'm at the point in the firmware where I'm going to be jumping through the FAT to find the right cluster.
At this point, I've made the decision to only support FAT16. This allows for using SD Memory Cards up to 4Gig (only).
But an interesting limitation on the lower end has just come into question.
If we use cards that are 64Meg to 4Gig, I can keep my cluster counting to a single byte, which makes things easier and faster. But if I have to support 32Meg or less cards, then the clusters need to be counted with 16 bit variables, still do-able, but it will take a bit more time.
I think the time difference won't be a major factor... and I'm leaning towards 16 bit counters, but I'd like to hear your opinions on this. Does anyone out there have 32Meg SD memory cards?
Searching ebay, it's curious to see 8Meg SD cards!
The average price of 16Meg to 256Meg is about $7
The 512Meg are about $14
and the 1Gig are about $5
Cheers,
Josh
--
You received this message because you are subscribed to the Google Groups "N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout. |