Baslinux mailing list

[Sindi Keesan <keesan AT iamjlamb.com>]

On Sat, 31 Jan 2004 3aoo-cvfd AT dea.spamcon.org wrote:

> Sindi Keesan wrote:
> >
> > Usually it all goes well until I put in disk 2 and 
> > hit space bar and get Divide overflow.    
> 
> So everything is correctly assembled in the ramdisk (c:):
> loadlin.exe, zimage and baslinux.gz?  And all of them
> have the same length as usual?  


Zimage is apparently broken in the ramdisk because it has been copied from 
a broken zimage (bad copy) that was made to the floppy disk by your 
make_fd program, which uses fdimage to copy a disk image to just part of 
the disk.  Then when zimage is copied, something goes wrong.  We have 
ruined 5 or 6 previously perfect floppy disks, after running scandisk 
first.  Once I run make_fd, they have bad sectors, and it is always zimage 
that is bad.  I cannot copy zimage from  that floppy disk even to the hard 
drive or to a ramdisk that I have made after booting in DOS.  

A different floppy drive stil did not work - it produced gibberish from 
the first disk, even tho scandisk did not find problems on it afterwards.
This is on the same (Cyrix) computer that usually gets divide overflow but 
one time got gibberish when loading disk2 on the first floppy drive.

> 
> > One time while copying zimage from a: to c> (ramdisk) 
> > I got a string of gibberish with hearts and happy faces 
> > and the computer froze up and had to be powered off and 
> > on again.  
> 
> So the computer froze up on a simple copy command?

Yes, but usually it just won't copy (I forget the error message - Cannot 
write or some such thing).

> It would appear that the ramdisk is using RAM that 
> is already in use.  vdisk is an old ramdisk maker 
> (from DOS 3.3) -- perhaps it is being tripped up 
> by the RAM allocation method used in that computer.
> Does it, by any chance, share its RAM with the video 
> card?  Or do anything else funny with its RAM?  Or
> have any unusual RAM settings in the BIOS?

> You might try using a different ramdisk maker (that
> might necessitate SYSing the floppy with a more recent 
> version of DOS).  Keep in mind that if you use a different
> DOS, the ramdisk will probably not come up as C:.

We tried this.  Same problem with MS DOS 6.22.  This computer does not 
share RAM with the video card, though the third one does (the one that 
does not even load disk2 at all).  I don't know of any unusual RAM 
settings.  But this is not a problem of copying a good file (zimage) to 
RAM.  The file on floppy disk is already bad. I can copy the other files 
to ramdisk okay including baslinux.gz.

Jim wonders why you did not make a full 4M RAM disk, but something just 
under that.  I think he may make an 8M disk and give instructions how to 
change the size by editing autoexec.bat so that people will stop asking 
why you don't make it larger.

 
> > It appears that zimage is not being copied correctly to 
> > drive C> (ramdisk) from drive A: (floppy disk).  
> 
> What size is zimage after the copy?  If it is the correct
> size, try copying it back to a different floppy and see
> if that will boot from HD (with the normal boot).

I cannot copy that zimage from floppy disk even to the hard drive.
Or manually to your ramdisk or to our ramdisk after we boot in dos and 
make one.  Zimage gets messed up when your make_fd.bat puts it onto the 
floppy disk and cannot be read, and the floppy disk also acquires bad 
clusters at the same time.  It scandisks fine before, and afterwards 
always has bad clusters.  Reformatting does not help, there seems to have 
been physical damage.  Antoher flopy drive did not help either.  Or other 
disks.  We wrecked 5 or 6 already.  

> > This computer has EDO RAM - 4x8M SIMMs.  The Intel has 
> > 4x16M FP SIMMs. The AMD has 2 DIMMs.  I doubt that they 
> > all have bad RAM.  
> 
> It's worth doing a RAM check.  As you know, DOS works
> quite happily with bad RAM.  Linux does not.  If you 
> don't have a proper RAM checker, have a google for
> memtest.  It creates an auto-booting floppy that very
> thoroughly checks all RAM.

The three computers all work perfectly with linux (now that I have fixed
the reset problem that was due to timing) other than not making these
disks with fdimage so I think the memory must be okay.

> > 4DOS also had some trouble accessing the ramdrive.  
> 
> So those computers are 4DOS incompatible?  Sounds like
> you've got some fussy hardware there.

I don't recall the exact problem with 4dos but it may have been that Jim 
was trying to look at zimage.  4DOS works perfectly otherwise.  I was not 
watching him at the time but he said things froze up.  He does a lot with 
4dos on all our computers and never had problems until he hit that first 
bl2 floppy disk with it.

He is working on something that will avoid the need to use fdimage or a
disk image, and just let people make a boot disk and a second DOS disk and
copy the needed files to it, probably the ones that you put together,
using your autoexec.bat etc, but not make_fd.bat that you provided.
And maybe give instructions how to make ramdisks of different sizes.  

> > Cheers,
> Steven
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