hello, everybody I use a USB key on my PC under MS-DOS. when I delete files on the USB key with an another PC and I replug it on my PC under MS-DOS then the DOS don't see that the files is delete. Do you know the DOS function that update or reset the "internal file system" or "drive parameter block" to update the new value of USB key. The big problem in DOS that he doesn't see when you unplug and plug the key and so he doesn't update the modifications and I don't want restart the PC every time. thanks for your help. Philippe
"Jim Leonard" <MobyGa...@gmail.com> a écrit dans le message de news: 3b116169-b46b-4187-8fa9-6e04dfb03...@m73g2000hsh.googlegroups.com...
> On Jun 27, 8:15 am, "PM" <philippe.meyn...@laposte.net> wrote: >> I use a USB key on my PC under MS-DOS.
> How do you do this?
in fact my BIOS PC recognize the USB key automatically like a floppy. A floppy with 32MB memory even if my USB key is 128MB memory. 32MB is enough for me, it's only for transfer files on other system. So like my USB Key is seen like a floppy , I can unplug and plug easily. So when I delete a file on other PC then my DOS don't see the modifications.
On Jun 27, 9:49 am, "PM" <philippe.meyn...@laposte.net> wrote:
> "Jim Leonard" <MobyGa...@gmail.com> a écrit dans le message de news: > 3b116169-b46b-4187-8fa9-6e04dfb03...@m73g2000hsh.googlegroups.com...
> > On Jun 27, 8:15 am, "PM" <philippe.meyn...@laposte.net> wrote: > >> I use a USB key on my PC under MS-DOS.
> > How do you do this?
> in fact my BIOS PC recognize the USB key automatically like a floppy. A > floppy with 32MB memory even if my USB key is 128MB memory. 32MB is enough > for me, it's only for transfer files on other system. So like my USB Key is > seen like a floppy , I can unplug and plug easily. So when I delete a file > on other PC then my DOS don't see the modifications.
But what DOS do you run, and how does it show up as a drive letter?
> hello, everybody > I use a USB key on my PC under MS-DOS. when I delete files on the USB key > with an another PC and I replug it on my PC under MS-DOS then the DOS > don't see that the files is delete. > Do you know the DOS function that update or reset the "internal file > system" or "drive parameter block" to update the new value of USB key. The > big problem in DOS that he doesn't see when you unplug and plug the key > and so he doesn't update the modifications and I don't want restart the PC > every time. > thanks for your help. > Philippe
If this is what I think it is, your BIOS isn't emulating the floppy disk change line. You may be able to send a reset drive service call to the BIOS.
using DEBUG
-a 100 xor ah,ah mov dl,0 <- drive number int 13h int 20h -rcx :8 -nreset.com -w -q
It has been a while since I have used DEBUG, so I hope that is the write sequence.
Make sure you use the correct drive number, 0 for the first floppy, 1 for the second, 80h for the first hard drive, etc.
If the BIOS is emulating the USB flash as 32meg, it probably is 80h instead of 00h, though I have never tried it myself.
I don't remember if the reset service clears the change line or not. However, you can try it.
On Fri, 27 Jun 2008 15:15:01 +0200, PM wrote: > hello, everybody > I use a USB key on my PC under MS-DOS. when I delete files on the USB key > with an another PC and I replug it on my PC under MS-DOS then the DOS > don't see that the files is delete. > Do you know the DOS function that update or reset the "internal file > system" or "drive parameter block" to update the new value of USB key. The > big problem in DOS that he doesn't see when you unplug and plug the key > and so he doesn't update the modifications and I don't want restart the PC > every time. > thanks for your help. > Philippe
Try Ctrl + C when in the drive. It used to work for floppies that were changed without the OS noticing.
It if helps, I notice that after I have removed a "floppy" 1.4 Mb diskette from a drive, the Windows DOS emulator still has a copy in memory of the directory of that diskette, and I have had the next disk directory damaged by not immediately requesting a directory listing of the new disk inserted, before writing a new file to the disk I just inserted. It only has happened to me on Windows systems (and a litttle too many times), not with real DOS.
So if you cannot easily do a reset, at least try DIR myusbkeydisk: first like " DIR B:"
Thanks I have already try it. here is what happen exactly: When I deleted the file on another system, the reset drive Bios function see that the file is deleted but the space memory free on the USB key isn't changed!! After power off /power on the system so the memory free on the Key is OK ! Here is my configuration : Panel PC with HDD 40gb(C:) no floppy,128Mo,Pentium M intel 1 Ghz.DOS 6.22. I boot with my HDD with a USB key plug see like a floppy (A:) on my key there is no os only files data. I can unplug and plug my Key with no problem. So when I boot the free memory space on my Key is OK and when I delete the files of my key on another PC then my system DOS don't see the memory space free?
> "PM" <philippe.meyn...@laposte.net> wrote in message > news:g42p4m$a5k$1@aioe.org... >> hello, everybody >> I use a USB key on my PC under MS-DOS. when I delete files on the USB key >> with an another PC and I replug it on my PC under MS-DOS then the DOS >> don't see that the files is delete. >> Do you know the DOS function that update or reset the "internal file >> system" or "drive parameter block" to update the new value of USB key. >> The big problem in DOS that he doesn't see when you unplug and plug the >> key and so he doesn't update the modifications and I don't want restart >> the PC every time. >> thanks for your help. >> Philippe
> If this is what I think it is, your BIOS isn't emulating the floppy disk > change line. You may be able to send a reset drive service call to the > BIOS.
> using DEBUG
> -a 100 > xor ah,ah > mov dl,0 <- drive number > int 13h > int 20h > -rcx > :8 > -nreset.com > -w > -q
> It has been a while since I have used DEBUG, so I hope that is > the write sequence.
> Make sure you use the correct drive number, 0 for the first floppy, > 1 for the second, 80h for the first hard drive, etc.
> If the BIOS is emulating the USB flash as 32meg, it probably is > 80h instead of 00h, though I have never tried it myself.
> I don't remember if the reset service clears the change line or > not. However, you can try it.
> Thanks > I have already try it. > here is what happen exactly: > When I deleted the file on another system, the reset drive Bios function > see that the file is deleted but the space memory free on the USB key > isn't changed!! After power off /power on the system so the memory free on > the Key is OK ! > Here is my configuration : Panel PC with HDD 40gb(C:) no > floppy,128Mo,Pentium M intel 1 Ghz.DOS 6.22. > I boot with my HDD with a USB key plug see like a floppy (A:) on my key > there is no os only files data. > I can unplug and plug my Key with no problem. > So when I boot the free memory space on my Key is OK and when I delete the > files of my key on another PC then my system DOS don't see the memory > space free?
> and yet , Thanks a lot for your helps. > Philippe
You can take the USB key to another computer, delete a file, then bring the USB key back to original computer, and see that the file has been deleted, but the freespace value has unchanged. i.e.: when you do a dir listing, the amount of space left on the disk is unchanged, but the delete file is not listed. Is this what you are saying?
Well, it could be one of a few things.
1. the OS you used to delete the file, marks the files dir entry as deleted, but does not free the fat chain, if indeed the USB key is using FAT. This may be due to some type of undelete mechanism the deleting OS uses.
2. The OS on the original machine may be storing the freespace amount in memory so that it doesn't have to calculate it each time you do a dir listing, which is a slow process. However, I don't remember DOS doing this.
Is it a true DOS you are running on the original machine, or is it a DOS window under Windows? If it is a DOS session under Windows, I have seen similar results using a floppy disk.
Before you insert the USB key back into the original machine, try to do a dir listing of that logical drive. This may tell the host OS that there is no disk in the drive. Then insert the USB key and do another dir listing.
The way it sounds, you are using a DOS session under the Windows95 family. Win95/98/ME family.
> "PM" <philippe.meyn...@laposte.net> wrote in message > news:g4a588$doj$1@aioe.org... >> Thanks >> I have already try it. >> here is what happen exactly: >> When I deleted the file on another system, the reset drive Bios function >> see that the file is deleted but the space memory free on the USB key >> isn't changed!! After power off /power on the system so the memory free >> on the Key is OK ! >> Here is my configuration : Panel PC with HDD 40gb(C:) no >> floppy,128Mo,Pentium M intel 1 Ghz.DOS 6.22. >> I boot with my HDD with a USB key plug see like a floppy (A:) on my key >> there is no os only files data. >> I can unplug and plug my Key with no problem. >> So when I boot the free memory space on my Key is OK and when I delete >> the files of my key on another PC then my system DOS don't see the memory >> space free?
>> and yet , Thanks a lot for your helps. >> Philippe
> You can take the USB key to another computer, delete a file, then > bring the USB key back to original computer, and see that the file > has been deleted, but the freespace value has unchanged. i.e.: when > you do a dir listing, the amount of space left on the disk is unchanged, > but the delete file is not listed. Is this what you are saying?
> 1. the OS you used to delete the file, marks the files dir entry > as deleted, but does not free the fat chain, if indeed the USB > key is using FAT. This may be due to some type of undelete > mechanism the deleting OS uses.
> 2. The OS on the original machine may be storing the freespace amount > in memory so that it doesn't have to calculate it each time you > do a dir listing, which is a slow process. However, I don't remember > DOS doing this.
> Is it a true DOS you are running on the original machine, or is it a > DOS window under Windows? If it is a DOS session under Windows, I > have seen similar results using a floppy disk.
it's a TRUE DOS (MS-DOS 6.22)
> Before you insert the USB key back into the original machine, try > to do a dir listing of that logical drive. This may tell the host > OS that there is no disk in the drive. Then insert the USB key > and do another dir listing.
good idea. so, when we try to do a dir listing of A: withou USB key -> Problem on drive A: ->OK insert the USB key , dir listing -> OK and the memory space free is OK Then there is therefore definitily a function which exists to make it !!! I seached with BPB (bios parameter block) ,DPB ( drive parameter block) but without succes! can yopu help me
>> Before you insert the USB key back into the original machine, try >> to do a dir listing of that logical drive. This may tell the host >> OS that there is no disk in the drive. Then insert the USB key >> and do another dir listing.
> good idea. > so, when we try to do a dir listing of A: withou USB key -> Problem on > drive A: ->OK > insert the USB key , dir listing -> OK and the memory space free is OK > Then there is therefore definitily a function which exists to make it !!! > I seached with BPB (bios parameter block) ,DPB ( drive parameter block) > but without succes! > can yopu help me
DOS is resetting the Disk Parameter Block entry (DPB). Without going and looking, I think the List of Lists points to this DPB list and there you can modify the first entry, as long as the first entry is your USB disk.
If you are using DOS 4.0 - 6.0, then change the value at 1Fh to 0FFFFh.
However, I don't recommend modifying it directly. You could really mess something up if it wasn't done correctly. If this is the only thing you got, though, make sure you do it correctly.
