From: Paul Guyot (pguyot_at_kallisys.net)
Date: Tue Oct 21 2003 - 07:13:11 PDT
Aux environs du 21/10/03 à 9:36 -0400, sous le titre "Re: [NTLK] FAT
Support through APIs: Was Re: newtontalk", Victor Rehorst prit sa
plus belle plume pour écrire les mots suivants:
>I figured that by now, had you wanted to do this, it would be done :)
Heh. It's funny because we discussed this earlier, when some people
wanted to do backups by just copying the file.
I don't recall the figures yet, but the transactional store engine
uses a lot of CPU and slows down transfers a lot. This is why the
cache speeds up the transfers that much. I continue to wonder if I
did design it properly (at that time I had no idea of the kind of
requests the system would do), i.e. if direct object access with some
tricks (a kind of hash function) was the good choice or if I should
have used B-Trees (or some index).
Still, doing something over FAT would slow down things more and the
amount of work to have a reasonable speed for that is much superior
than the work to do a backup on a FAT partition, hence the choice
I've been explaining in this thread.
>Have you ever seen an OS that supports a partition table on a CF card?
>Actually I should try this right now with Win2000!
>
>-I take my 4MB CF card (FAT formatted), and partition it into two Newton
>stores with ATA Support.
When you formatted the card in your Newton, it wrote a partition map
in the Newton Store Collection format. It didn't write a MBR or a FAT
Boot Sector with some FAT stuff.
As long as the OS reads the MBR, it should work. And even if it
doesn't read the MBR and expects some FAT stuff as on floppies, I can
increase the number of unused sectors at the end of the card and use
these for Newton data.
I'll bet on the MBR, though, since this is much cleaner and I'm
confident Windows do like Linux and MacOS X considering flash cards
like drives (hence accepting a partition map on them). Most (all?)
cameras also read the MBR.
What I'll do first for FAT Support is to implement the ability to
indeed have a Newton Store in a MBR structure. Instead of
FAT{12,16,32}, the kind of partition would be Newton Store (I already
found some unused 8 bits code I could use). Now that I have a camera
(well, being repaired) and a PowerBook, I can do this easily. Plus I
already decode the MBR properly (more or less, I wonder if weird
results people reported are for cards with no MBR), as in you get the
number of partitions and their size when you insert the card in the
Newton (you don't get the name but I don't decode the name yet).
Paul
-- Changement de baignoire. NPDS/NewtonOS: http://newton.kallisys.net:8080/ Apache/FreeBSD: http://www.kallisys.com/ -- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/
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