Re: X-IDE and Power Cartridge

From: Jim Brain (
Date: 2007-12-30 08:31:32 wrote:
> On 2007-12-28, at 01:43, Jim Brain wrote:
>>> P.S. A different subject - I don't know why but it seems to me that 
>>> nobody likes the idea of (re)using IDE64 partition scheme and 
>>> filesystem.. I wonder why..?
>> We are defitely using the IDE64 Partition Scheme, as it uses the std 
>> IBM IDE partition scheme.
>> If we implement the IDE64 FS, we should absolutely use partition type 
>> 0xcf (the one they use).
> Well - the word "absolutely" doesn't fit IMHO. IDEDOS is still being 
> developed and I don't think it would be impossible to persuade the 
> author(s) with reasonable arguments to change what is used there - if 
> that is needed for some reasons.
I misspoke.  IDE64 does not really use the IDE partition scheme.  It has 
it's own scheme.  It uses an IDE partition entry to mask off the entire 
chunk used for IDE64.  It uses it's own partition "directory" and such.

As such, I'm not wild about the scheme IDEDOS uses, but since I'm not 
typically a DOS author, take my thoughts with a grain of salt.  I think 
a better approach would be to use the IDE standard partition scheme, 
making the partition scanning code simpler (scan the entire partition 
chain, including FAT16/32 partitions, and any other partition type folks 
want to implement.

> a) partition type does not necessarily denote a filesystem in use (as 
> you noted yourself), and
> b) I am not 100% sure that "IDE64 will no doubt assume an xyz 
> partition is IDEDOS FS" - I'd have to check that but I wouldn't be 
> surprised if the superblock was checked at least for the FS signature
Yeah, it checks lots of other stuff.  It looks like the 0xcf partition 
type is there so you can use the drive in another computer and not hose 
the IDE64 partition(s)
> As I wrote - reading FAT is supported in the current IDEDOS. For 
> effective CBM use there might (?) be limitations preventing it usage 
> without major workaround/encapsulating effort. How about Microsoft 
> royalties. I heard (correct if wrong) that one has to pay licence fees 
> for write support.
As I read it, if you use the format at all (read or write or both), you 
need to pay.  I'm not sure how Linux et al get around this.  IDE64 is 
also not in the clear, as I read the IP.


Jim Brain, Brain Innovations                                      (X) 
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! 

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