Hello, Mike.

-=> MIKE ROSS wrote to MATT MC_CARTHY <=-

 MR> Yes, of course but isn't the drive number irrelevant since the hdc
 MR> communicates properly? In any case I made a mistake in stating it was a
 MR> Maxtor since it is in fact a Micropolis 1558-15, with 18ms step rate.

My old book by Scott Mueller (Sixth Edition, 1996)doesn't have the -15
model listed, but it has Micropolis 1558 at 1223-15-34 (319MB).  This is
vice your label's 1224-15-36.  I just worked with a few ESDI's and
that was some years back, but seems I vaguely remember their being
formatted to 34 vs 36 SPT so the extra 2 sectors could be used for some
function - - maybe mapping out bad sectors.


 MM> The "330Meg" is a number you will never see.  I just ran
the math for
 MM> your reported 270Meg, and even with the "1048..." calculation comes
 MM> out short at about 283Meg.  I seem to recall those formatting to
 MM> 318Meg.
 MM> Working with 1024 x 15 x 36 comes out to 276Meg, and formatting will
 MM> likely use up that 6 Meg to arrive at or near your 270 Meg.  From that
 MM> point, it does look like you are up against the '1024 cylinder
 MM> barrier'.

Waitaminnit - maybe Matt punched a wrong key.  My new Christmas Casio
calculator gets 1024 x 15 x 36 x 512 as 283.1MB, which FDISK would
divide by the 1.0485 you mention below and call 270MB. Looks like 1024
cylinder limitation is as work here, OK.

Sometimes BIOS SETUP will let you enter a value in the User-Defined CHS
parameters which it will not support.  So maybe your machine's bios
would accept 1224, but only format the first 1024.

 MR> The factory lable states 382M capacity but I suppose that is counted
 MR> "by the bit" which includes the ECC bits and other
engineering stuff
 MR> but some hd listings have it as 338M and as I said the mb bios setup
 MR> finds 330M with C-1224, H-15, S-36. I also came up with 330M if 1Meg is
 MR> 1024K, but if dos calculates 1M as 1048.5K (i.e. 1024^2) that would
 MR> still be 322M right? Minus the formatting I suppose it may reduce by
 MR> 1/10'th at most so still leave at least 300M (in dos Megs)... Why
 MR> does everybody insist on a different definition of 1Meg? :(


 MR> Thanks for your kind words. I did the hdc's bios format and it gave the
 MR> full drive capacity. The controller docs specifically mention disabling
 MR> the bios for dos other than 3.x etc which has a 32M limit and assigning
 MR> the whole drive to a single volume before partitioning with the
"other"
 MR> dos.

 MR> What I think the current problem may be is dos 6.22, when reading the
 MR> present 90M active partition, sees a "previous" 270M
value written in
 MR> it by dos 5.0 and decides the extended partition can't be more than
 MR> 180M. That's the only explanation I can make sense of. I'll let you
 MR> know if removing the last active partition restores the full capacity
 MR> otherwise I'll have to go back to the hdc's bios and try again.

Seems like it is only LLF'd to 283/270MB now.  If FDISK confirms
this, maybe the HDC BIOS can accept more than 1024 cyls and you can LLF
it to get over the 300 MB mark.

Good luck - - -  JimH.

... Good old days?  Heck, Jim, what was good about them? - Bubba.
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