Hard Drive Diagnostics accessing Status Register Information

In a working environment, a user cannot access Status Register Information, since I/O ports are protected by a Kernel layer.
But when you need to determine whether a hard drive is broken or not, and afterward figure out what's the problem, being able to read the Status Register is fundamental. It's the fastest and most precise way to understand if there's something wrong with your hard drive and what exactly is wrong with it.

Let's take a step back. What is a status register in the first place? Let's find out.

An ATA bus typically has ten I/O ports that control its behavior. For the ATA primary bus, these I/O ports are usually 0x1F0 (the "I/O" port base) through 0x1F7 and 0x3F6 (the "Control" port base) through 0x3F7.

For the secondary bus, they are usually 0x170 through 0x177 and 0x376 through 0x377. Some systems or cards may have non-standard port locations for the ATA registers, in which case it may be helpful to consult the section on PCI to determine how to retrieve port addresses for various devices in the system.

The values in these tables are relative to the so-called port base; a port offset of 1 from the I/O port base refers to port 0x1F1 (0x1F0 + 1 = 0x1F1). This is done because the base port may vary depending on the hardware in any given system. Also, some of these I/O ports map to different registers based on whether they are being read from or written to.

The register status in the ATA protocol has the function of providing real-time information on the operating status of a peripheral that respects the ATA protocol.

T13 ATA committee

Status Register is an 8-bit value that reflects device status in real-time. Operating Systems don't show Status Register value, since do exists an internal data driver which does the job. Any Data Recovery Engineer *NEEDS* to check and analyze the device status register, which is essential to understand the current device status.

The device status register is specific information retrieved reading device physical ports.
The status register is one single byte with 8 state bits. In Challenger Rocket status register information is available in the bottom area in all PCIe Card diagnostic and data recovery tasks.

Hint: Data Recovery Professionals check status registers to instantly diagnose current device behavior.

The ATA register status can be acquired by querying the specific port of the controller (1F0h Primary or 170h Secondary or specific Card IO Port). For safety reasons, no software can have access to the computer's IO ports as they are for the exclusive use of the Kernel.

Older and obsolete operating systems that gave the user a chance to access I/O ports from userspace:

1. WINDOWS 95
2. WINDOWS 98
3. WINDOWS XP

If Device Status has BUSY bit set cannot receive commands.
The device will set the BUSY bit in every command/transfer command and should be unset at end of every command.
If the device sets busy bit after receiving a command and does not clear it resetting is needed.

If Device Status has a DWFT bit, usually a critical error occurs.
Some Seagate Models suffer from the DWFT Fault bug.
In those cases, the device needs firmware tweaks and repairing to proceed to successful drive image or recovery.

If Device Status has DRDY bit set can receive commands.
DRDY bit should be set at end of every command.

If Device Status has DREQ bit set some PIO ( programmed I/O ) transfer is running. DRDY bit should be unset at end of every command.

If Device Status has ERR bit set after a command error occurred and the transfer failed.
The user should investigate Error Status to identify error type.

After a successful power, the Hard Drive should clear the BUSY bit. If the Device remains in a BUSY bit status, some firmware issues exist ( on Seagate Hard Drives BUSY Lock issue is pretty common ). Keep in mind devices with the BUSY bit set cannot accept any command and cannot be recognized by any system.

After a successful power, Hard Drive which implements SATA/ATA Protocol should answer with DRDY + DRSC bits set. This means a correct operational mode.

If the Device sets DRDY in combination with ERR bit some hardware/firmware issue occurred.
Try to detect hard drives using 0xEC identification and check for lba availability.

• MHDD is a program that runs from a Command Prompt instance and, if needed, it'll emulate USB and read it like SCSI to inspect and assess USB storage devices. it analyzes the status of your hard disk drives and gets you accurate information about their mechanical components.


• Victoria HDD is a free hard drive tool that can be used to monitor the performance of your hard drive. You can use it to measure the performance of your hard drive and, in case of issues, perform some minor repairs. It will display your hard drive model, size, features, and erase and even restore data when errors are spotted.


• PC-3000 UDMA is the optimal hardware-software solution for diagnosing, repairing, and recovering data from damaged HDD based on SATA and ATA by using vendor-specific commands (for various capacities -from 500MB to 8 TB)to switch the drive into kernel mode. The PC-3000 UDMA coupled with the Data Extractor forms the PC-3000 UDMA Professional System that allows you to recover data from SATA, ATA HDD.


• Challenger Rocket is a Linux ChallengerOS 64 bit Package designed for data recovery purposes. It has been built to read hard disk drives with several types of damages and to perform a perfect hard drive image skipping damaged areas or lba blocks. Rocket uses an amazing IO Physical Protocol to get the most readable area from a damaged device. The Unique Reading Algorithm will bypass completely operating system queues, caches, and IO subsystems to get you into the hard disk drive hardware.

MHDD Main Screen

Victoria RU Status Register Values

PC 3000 Data Extractor

ChallengerOS Rocket Main Task Screen