I'm a little surprised you can't boot USB, though I vaguely
recall one Via C3 based board I have (not EPIA but a similar
PCChips version) had to have the USB thumbdrive formatted to
FAT16, and set to RMD-Floppy or something like that in the
bios... but this was easy enough to figure out because
pressing F8 before the system tried to boot a drive would
bring up a boot menu that listed everything it found and the
type of device it was considered.
Interesting, I just checked, I do not have that problem.. (and my BIOS
- phoenix BIOS - does have an option for USB-HDD, and no RMD-Floppy
option). I figured my MBRD just did not support it.
But
Turns out it is fine,, same as my other very different machine. I do
not know why it did not boot off USB "last time"(I had only tried it
on one day, must have done something wrong that day).
BTW, OT, The VIA EPIA it seems had 2 processor options. C3 and EDEN.
C3 was faster but had a fan. I chose EDEN, which was fanless. Anyhow,
back onto the USB thing.
I did run into a problem booting USB, which I have isolated somewhat.
ntoe- I have not retested this.. But I am fairly sure I did not slip
up in these tests.
HPUSBFW.EXE (the famous program by HP, for formatting a usb key), has
an option to either format as FAT32, or instead, to format as what it
calls "FAT". )
(I know that at one time, prior to FAT32. You had FAT16 and FAT. FAT
was considered to be FAT12. But nowadays, you have FAT32, FAT16, and
FAT12. But FAT12 is not mentioned much, and FAT tends to refer to
FAT16).
Windows does not say whether by FAT, it means FAT12 or FAT16.
So looking at a USB key, one cannot see that way with Windows which it
is.
However.. FAT16 has a 2GB limit
16 bits for addresses, some size per address. (2^16 * x = 2GB ) x
happens to equal 32K (2^5=32K). But it is easier to remember the 2^16
and the 2GB !
FAT12 has a 2MB limit (1.44MB when formatted.)
2^12 * 512K = 2MB
FAT12 is used for floppy disks.
I noticed that HPUSBFW.EXE when told to format as FAT, was formatting
disks > 2GB as FAT16, and they were still > 2GB in available
capacity.
And those USB keys, > 2GB , formatted as what HPUSBFW.EXE called FAT,
do not boot. (they do view in windows xp though, but that is
irrelevant)
Whereas USB Keys formatted by HPUSBFW.EXE as FAT32, do boot.
And those USB keys < 2GB, boot, even if formatted as what HPUSBFW.EXE
calls FAT - which is no doubt FAT16. Do boot.
The ones that fail/"do not boot", crash both my very different
computers, at the point in the BIOS, where it says Verifying DMI pool
data
One program that does display whether FAT16 or FAT12 is FDISK.. When I
booted off a USB key that booted. (a < 2GB USB key, formatted as
FAT16). FDISK saw it - as DOS does. And it said FAT16. So that
verifies that when HPUSBFW.EXE says FAT, it means FAT16. But it is
some mangled FAT16 when the drive is > 2GB.
Or perhaps not mangled.. but some Windows limit (and perhaps limit
from some or all BIOSs) on the "cluster size" with FAT16
Windows limit is not that relevant, but as a related note
and also, note that the USB keys I tried > 2GB, were 4GB
http://support.microsoft.com/kb/310561
"
The 4-GB partition limit is imposed by the maximum number of clusters
and the largest cluster size supported by the FAT file system. In
Windows XP, FAT16 is limited to 64K clusters. Multiply the maximum
number of clusters (64k) by the maximum cluster size (64K), and the
result is 4GB. In addition to Windows XP, Microsoft Windows 2000 and
Microsoft Windows NT 4.0 also support FAT16 volumes up to 4GB in
size.
FAT16 volumes larger than 2GB are not accessible from computers
running Microsoft Windows Millennium Edition (Me), Windows 98, Windows
95, or MS-DOS. The size limit for FAT16 volumes in these operating
systems is 2 GB. In other words, to maintain compatibility with
Windows Me, Windows 98, Windows 95, or MS-DOS, a volume cannot be
larger than 2 GB. For additional information about FAT16 drive and
partition size limits in Windows Me, Windows 98, Windows 95, and MS-
DOS, click the article numbers below to view the article in the
Microsoft Knowledge Base:
"
So maybe in that list
"FAT16 volumes larger than 2GB are not accessible from computers
running ...."
One could add that not just Win9X, but BIOSs, or some BIOSs, do not
support it either.
On another related note- I seem to recall something like, from a LUA
(i.e. non administrative) account, you cannot read FAT32. But that is
not that relevant.
I guess the way to analyse some of these things is to write a program
to format disks! Or read FAT perhaps! I know scott mueller wrote
something analysing FAT16/32 in his UGRP book. And the starman website
has stuff.
Keep in mind that I use CF-IDE mostly for installation or
utilities, not running the OS (though i have done so in the
past). For (windows/etc) OS the CF card can be rather slow
unless you're using a fairly modern CF3.0 spec'd card and
the IDE adapter supports DMA. This is important to get it
out of PIO mode which limits it to about 6MB/s.
Note that some cards may occasionally be listed as only "CF
spec" or similar but they dont' come out and say which
version of the spec. You'd want CF3 or CF4 spec for fast
cards with this support. On the other hand if you just want
to get the job done as cheaply as possible, these days an
older PIO mode 2GB card can be had for under $15 and a
cheapie eBay CF-IDE adapter for about $3 + S/H.
It is pretty great just how low power consumption can be
using a CF card. I have a NAS enclosure on my desk that I'm
playing around with, which can also webserve and do P2P. I
temporarily put a CF card in it and it now consumes about
3.8W booting, 2.6W idle. It'd take more than that just to
power the hard drive.
what is a make/model of a good NAS enclosure for CF cards?
You mention slowness of CF I , but I saw a CF I card that did 133x
(20MB/s). Which is prob about the same as the newer type IIIs ?
for example
make- lexar , type I / type 1
make - Kingston, also CF 1, 4GB 133x
another that comes up is called Eagletec @ 150x. There seem to be
loads.
So that is fast, right? No need [for me] to bother with CF III
whatever advantage that has?
slightly OT note- i would probably be avoiding "microdrive" ones, they
prob make a noise. Good primer on compact flash cards - (I include a
bit of text from it so people can get it from the google cache if it
goes down) (archive.org is another option)
http://www.bobatkins.com/photography/digital/compact_flash_memory_cards.html
Compact Flash, SD and SDHC Memory Cards
"A common question from new digital camera owners is "which memory
card should I buy". The answer depends ......."
