On Friday, October 12, 2012 3:02:56 PM UTC+2, M.R.W Wills wrote:
> On Oct 11, 7:54 pm, Howerd <
howe...@yahoo.co.uk> wrote:
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> > On Thursday, October 11, 2012 7:37:40 PM UTC+2, Howerd wrote:
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> > > Hi All,
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> >
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> > > I have just released USBboot, a selection of three files to make a USB drive bootable :
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> >
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> > >
http://www.inventio.co.uk/USBboot.htm
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> >
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> > > USBboot.exe is written in the SwiftForth dialect of Forth.
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> >
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> > > FAT32ldr.bin and kernel.bin are writen in NASM.
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> >
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> > > USBboot is designed to allow colorForth or another operating system to be run from a USB drive. The colorForth port will be done ASAP...
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> >
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> > > Feedback welcome,
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> >
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> > > Enjoy!
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> >
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> > > Howerd
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> >
>
> > I have just released USBboot, a selection of three files to make a USB drive bootable :- Hide quoted text -
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> >
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> > - Show quoted text -
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>
> This is excellent! Thank you for sharing this, Howerd! I'll give this
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> a try tonight!
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>
>
> Regards
>
>
>
> Mark
Hi Mark,
Thanks for the comment :-)
Basically USBboot is the Windows version of cfDOS. I have been surprised by how much harder it was to achieve the same thing in Windows/USB compared to DOS/Floppy - maybe 10 x harder.
Firstly you've got the never ending battle to make anything work on the latest version of Windows. With Win7 you must "Run as administrator"...
Then there is BIOS USB versus Floppy Disk hardware - somehow floppy disk hardware got integrated into the PC glue logic in the same way on almost all PCs from the 1990's onwards. USB is way to complicated to fit into one 512 byte sector, so you have to use the BIOS.
Then USB drives can be formatted in at least two ways, with or without an MBR, with varying disk parameters, and there is only reverse engineered documentation about how a BIOS deals with this, and only guesswork about what Windows does.
Then there is LBA versus CHS - a comment on OSdev.org said that all BIOS's since the 1990's support LBA, and this is true of every PC and laptop that I have access to - so thankfully CHS is gone...
Then there is how Windows decides to format a USB drive - not only FAT12,16,32 or NTFS, but whether to use an MBR or not, and whatever it decides it will certainly not be the way the USB drive manufacturer did it.
And not forgetting my favourite, FAT32. There are just enough strange offsets and bizarre calculations to make the official MS document a challenging read.
I defined USBboot as "working" when it successfully made all of my USB drives (and an SDCard in a card reader) boot. This has taken a lot of evenings and weekends sporadically over the last year or so...
If anyone finds a USB drive that does not work, press 'C' to capture the important sectors to a file and send it to me :-)
Best regards,
Howerd