RE: IDE ATA Hard Drive with ATmega328p MCU as Controller Question

clem57 — Thu, 01 Jan 2015 10:49:56 GMT

Originally I tried to access the hard drive using Cylinder/Head/Sector (CHS) addressing, and it would not work properly. All of these early attempts were with a Western Digital 1.2 gig drive. I could read the first sector, C=0, S=0, H=0, also known as the Master Boot Record (MBR), but reading from other parts of the drive would not work. After much frustration, I discovered that the drive wanted to receive the Initialize Drive Parameters (0x91) command. I didn't find much documentation about this command on-line. I deleted all the code I wrote for CHS (except for printing info from the drive ID command).

Sounds like that may be your problem!

Cheers,

Clem

RE: IDE ATA Hard Drive with ATmega328p MCU as Controller Question

iexpress — Tue, 30 Dec 2014 07:13:45 GMT

After trying for a few hours, I managed to be able to read the first set of data after issuing read device id command.

Still unsure what the sequence is to write sectors, but when I try to read a sector, it only hands me the first entry.

In this screenshot, the last entry in the terminal shows as 0xED which is the lower 8 bits of the first entry of the Device ID command.

Supposedly we're supposed to read the data from register 0, but when I go to toggle the Read pin and reselect the Read pin, all entries after that are 0xFF, as if the entire device is disabled.

Any ideas what the proper sequence is for reading or writing to an IDE drive?

Thanks.

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