2.5 hard drive install - incorrect size !!!!

[beltrixx]

Hi everybody,

I'm having a problem while trying to install a 20 Gb 2.5" IBM Travelstar drive on my A1200. Seems impossible to get the correct size for the drive! instead of getting the 20 Gbs, I'm getting a 7.8 Gb size and don't
know how to fix it. I would appreciate some help.

Here's what I'm doing:

1. I'm booting from the AmigaOS 3.9 Emergency disk
2. Start HDToolbox from the Emergency disc. I choose scsi.device (version 43.35)
3. Click on "Install drive"
4. Accept the requester about data loss and try to define a new RDB for the drive.
5. Enter the drive parameters, as shown on the top cover of the drive: 16383 cyl, 16 heads, 63 sectors.
6. Size is autoadjusted to 7.8 Gb !!!!!!
7. If I choose "partition drive" 4 default partitions appear (about 2 Gb each) ...

The most curious thing is that if I use HDToolbox from the WB 3.1 disk sets, and choose "Change Drive Type" -> "Edit old" (to edit the RDB) --> "Read Configuration" it reads up to 38760 cylinders instead of the 16383 labeled
on the drive !!!! although the drive sizes displayed are also incorrect too...

I would like to know what should I do to have my hard drive detected properly...don't know what to do and don't know what's the problem.

My hardware config :

A1200 with Microbotics 1230 Accel card. Not towerized.
Kickstart 3.1 ROM
2Mb Chip RAM + 32 Mb Fast.
20 Gb 2.5" IBM Travelstar laptop drive as master
LG 52x CDROM drive as slave.

Thanks in advance

[adolescent]

38760 is (probably) the real number you need to put in.  The 16383 is there for compatibility with old PCs and will limit you to ~8GB.  

cylinders * heads * sectors per track * 512 = size in bytes

Edit: added info.

[Thomas]

With 38760 cyls / 16 heads / 63 sectors you get 20,003,880,960 bytes (20 billion bytes). Why do you consider this being wrong ?

HDToolbox will display 18,6 GB. That's normal for such a drive. Manufacturers calculate with 1,000,000,000 bytes per GB while HDToolbox uses 1,073,741,824 bytes per GB. That's marketing, nothing else.

Bye,
Thomas

[beltrixx]

Thank you Thomas & adolescent for your replies.

It's a pleasure being a member of this helpful community.

Regards from Spain,

Manel.