NTLK [semi OT] Filesystems specification

From: Paul Guyot (pguyot@pnm-consulting.com)
Date: Thu Jun 15 2000 - 16:56:15 CDT

Hi all,

I inserted the 16 megs compact flash card in a PowerBook (my
Partner's G3), and it only accepted to format it as DOS.
I guess I cannot make an Apple partition map to store the Newton
stuff, at least with PCMCIA cards. Has anyone here used PCMCIA ATA
cards in Apple laptops?

Hence, the original plan which was to use Apple Partition map is to
be forgotten. The trouble is that it was the only one I know, and I
could have tried to use a Disk Image on my desktop (which doesn't eat
PCMCIA cards).

Hence my question: which partition map do you want, which filesystem
do you want and where to find the according documentation?

Anyway, the cards will accept at least two formats:
a/ partitions as defined somewhere. Advantage: will allow foreign
file systems (Gopi wants the Unix filesystem with the Standard
Library, not sure it will be done by tomorrow, but anyway).
Inconvenients: eats some sectors to declare partitions. One should
ensure the foreign unfriendly computer will eat the card with a
Newton (or several) partition.
b/ Newton only card, with a minimum of one sector header.
The header will act as a mini partition map for Newton stores
(remember: the limit is 32 MB).
The same data will be found on a Newton partition with solution a,
i.e. several stores per partition. I thought that if we use large
disks, it will be better to make several stores definitions in one
sector rather than one per sector as with Apple Partition format.
Besides, there is a limited number of partitions, for any format, and
therefore, having our own store list allows as many partition as we
want. Finally, the store list will include data which may not be
stored in a partition entry in a partition map, hence requiring an
additional sector. I really think it is the best solution, but since
all my code is made today to read and write sectors, you can try to
change my mind.

Apparently, there is a difference between voyager newtons (2.1
devices) and 2.0 newtons concerning the PCMCIA support. (maybe it's
just because there are the possibility for two slots). And the Newton
eats a (private?) filesystem with U at the end (55AA) of the first
or second block (not already sure). And it looks for informations on
the same block at various offsets, it seems to be like a table. And
apparently, it would like to load a driver which would be on the disk
(because it does not find this, it says no).

Fortunately, it seems that the Newton loads the internal packages
before wondering at what's in the slots, hence there is no need for a
driver on the card, even at startup. Besides, this would take useless

Any thought?

BTW, I have setup an NPDS server with my Newton in order recieve
comments and suggestions about the current status of my Newton
projects (updated daily). (just tell me which project you want to be
developed first, and so on). It can be found when I don't use my MP
and my Internet connection, mostly when sleeping (I am at GMT+2),
registered at the NPDS tracker ( and at
Since I did some changes to NPDS, there may be some bugs, hence don't
hesitate to contact me if there is something wrong.

(Special thanks to Tim for the Ethernet card)



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