🚀 go-pugleaf

In article <292851037wnr@alankh.demon.co.uk>
           Alan@alankh.demon.co.uk "Alan Hiscock" writes:

> Hello all,
> In common with many others, judging by the threads on hard drives, I 
> have problems. I am attempting to instal a 1G Quantum hard drive 
> as a slave, but the disk parameters which auto-load are as follows:
> Type 48
> Cyl 2112
> Hd  16
> Pre 903
> LZ  903
> Sec 63
> Size 039
> The latter size of only 39Mb makes me reluctant to proceed with 
> partioning. Incidentally, Norton Utilties finds the correct size.

The reason for this is that the PC BIOS only supports up to 1024 
cylinders. The BIOS is taking 2112 modulo 1024, so it thinks the 
disk has 64 cylinders.

So 64cyls*16hds*63spt*512bytes/sec=33,030,144 bytes.

Norton gets the size right because it reads the info direct from
the CMOS, rather than asking the BIOS. Other disk utilities may
report the 39Mb figure.

You need a new motherboard or BIOS with LBA support, or an enhanced
IDE controller card with BIOS, to get the full capacity of this drive.

If you're not prepared to do this, you can set the number of 
cylinders to 1024, which will give you a 528Mb drive. 

Alternatively, you may be able to use something like Ontrack, 
which loads a driver before starting MSDOS to replace the BIOS 
Int13h layer, but I hesitate to recommend software solutions for
something as fundamental as hard disc access. Many people do use
it and have no problem, though.

There is a lucid and concise explanation of the BIOS limitations
on hard disc size, Int13h, and EIDE in PC Plus magazine, December
1995, page 425, which arrived through my letterbox this morning.
Worth reading.

You may also want to look at Peter Herweijer's superb EIDE FAQ; 
send mail to 

pieterh@sci.kun.nl 

with a Subject line of "ATA-2 FAQ please". Note that he warns: 
"the body of the message will be ignored. Anything fancy will 
probably break the mail server and cause it to send you an uuencoded 
coredump" :)

cheers,

-- 
Mike Tomlinson