[Coco] Super IDE vs. Drive Pak

[Mark Marlette]

John,

I haven't read the spec since 2003/2004 when the S-IDE came out.

Like all specs they update, accommodate larger devices, etc. SD, SDHC for example.

I knew at the time that we wouldn't go beyond the spec then. Larger high end cameras still use CF, just plain FAST and rugged! The cost of a 60GB CF or larger is $$$$.

The other day I was in the woods with one of my many trail cams, SD based. Gloves on as it is getting cold in MN, went to slide the WP switch and tore it right off. #$%!@# They don't work without them, pull state wrong. So a mile walk, as I didn't bring a back up, it was back up.

My fault all the way, just need to be careful, bull in a china shop, that is me.....

The S-IDE is rugged as well. Since 2004 I have had three repairs that involved removing the CPLD on a fine pitch rework station a work. Nice to have, still not a easy job, 100 pins on a TQFP size of a postage stamp. All of these failures were due to the cartridge being moved while the CoCo was powered. Not a fault of the device or design. Stuff happens.

As a designer, the risk is worth it. The power of technology is wonderful, doing things we would have spent months doing in mere moments. Anyone that has mastered the tools will say the same. :)

Regards,

Mark
Cloud-9
http://www.cloud9tech.com


----- Original Message -----
From: "John Kent" <jekent at optusnet.com.au>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Wednesday, November 16, 2011 8:28:13 AM
Subject: Re: [Coco] Super IDE vs. Drive Pak

For some reason I thought CF cards were limited to 2GB.
I can't remember why I thought that.
If you look at the IDE register interface you'll see you should be able 
to address up to 137GB.
For 160GB drives and beyond, I'm not sure what happens.
There must be some additional registers or bits somewhere.

A2 A1 A0 D15-D8   D7-D0
0  0  0  Odd Data Even Data
0  0  1           Error / Feature
0  1  0           Sector Count
0  1  1           Sector Number    LBA  7- 0 (                  256 * 
512 =         131,072)
1  0  0           Cylinder Low     LBA 15- 8 (            256 * 256 * 
512 =      33,554,432)
1  0  1           Cylinder High    LBA 23-16 (      256 * 256 * 256 * 
512 =   8,589,934,592)
1  1  0           Select Card/Head LBA 27-24 ( 16 * 256 * 256 * 256 * 
512 = 137,438,953,472) * 2 Drives
1  1  1           Command/Status

C/D/H = 1, LBA, 1, Drive, Head (LBA 27-24)

137.5GB * 16 = 2.2TB but then you lose the LBA and Drive bits
(from the Apacer Compact Flash AP-CFXXX22 specification sheet)
It assumes 512 byte sectors. I believe 2TB hard disks and beyond use 
4096 byte sectors which are only readable by Windows 7 and beyond and 
not windows XP so perhaps you can squeeze another factor of 8 out of the 
IDE register set.

John

On 16/11/2011 11:34 PM, Mark Marlette wrote:
> All,
>
> Good thread!
>
> Input has been gathered and we will be making some changes at Cloud-9 on the SuperIDE product based upon this great feedback. More to follow on that.
>
> Just want to clear this misconception. The SuperIDE DOES NOT have a size limit other than the CF spec itself. If you want to plug a 64GB CF, do so. The limitations are placed upon it are by NitrOS-9 and or HDB-DOS. This is a 24bit LSN, which is a bit over 4GB, IIRC. So is it practical to have a 4, 8, 16, 32,64GB CF on the CoCo? No, but if you want to you can.
>
> I ship with a 256MB just because it is a sweet size. 84MB partition for HDB-DOS and a 127MB partition for NitrOS-9, with another small partition with the remainder available. The reason for this is that there as several utilities under OS-9 that ASSUME a cluster size of one! Run those on a non 1 cluster size and POOF-BAM goes the drives structure. IMHO, not worth it. B&B are the biggest offender. Who would have thought we would be here today doing what we are doing? All GREAT tools, thus my basis of my partition sizes.
>
> How many people have more than 127MB of data/programs on their NitrOS-9 drive? Sure there are some. For those who want to have a 4GB partition, then you can do that on what ever size CF GREATER than that you select. Fill the 4GB partition up?? Not likely.
>
> Options are good. :)
>
> Any case, thank you all for the support and the great feedback. You will like the results. :)
>
> Regards,
>
> Mark
> Cloud-9
> http://www.cloud9tech.com
>
>

-- 
http://www.johnkent.com.au
http://members.optusnet.com.au/jekent


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