Floppys, Hard Drive Ports, CHS, CD-ROM..

Hard Drives:


IDE - Hardware Reference & Information Document - by Alex T. Ivopol


This document gives a lot of details about accessing and manipulating IDE disks directly, as an operating system would have to do. This document is heartily recommended for those who do not want to use the BIOS through VM86 mode. :)

Reading the harddisk using ports - by qark


This file describes the IO ports that are available on an IDE disk, as well as some example code to go with it. The sample code demonstrates reading and writing to the disk...

Direct disk I/O module for IDE disk controllers - by Alan Martin


This code example demonstrates direct IDE disk control, using the IO ports. This code does not use interrupts to drive the disk, but instead polls for the data. Also included is this test program.

How It Works -- CHS Translation - by Hale Landis


"Why is an understanding of how a BIOS works so important? The basic reason is that the information returned by INT 13H AH=08H is used by FDISK, it is used in the partition table entries within a partition record (like the Master Boot Record) that are created by FDISK, and it is used by the small boot program that FDISK places into the Master Boot Record. The information returned by INT 13H AH=08H is in cylinder/head/sector (CHS) format -- it is not in LBA format. The boot processing done by your computer's BIOS (INT 19H and INT 13H) is all CHS based."

IDE Interrogator - by Doug Merrett


"This program will interrogate an IDE hard drive and display the resulting details in a 'quick and dirty' fashion. This was knocked together one night after managing to get my hands on an IDE Hard Drive Technical Manual." Includes source code and a binary.

General Hard Disk Information:


Technicians' Guide to Hard Disks (ch 1) - by Nicholas Majors


"This booklet (now electronic) is published as a service of Data Recovery Labs. Its purpose is to provide the fundamental knowledge of concepts and terminology that is necessary to deal with the complexities of hard disk subsystems. It is not a technical reference guide and should not replace original documentation made available by manufacturers."

Technicians' Guide to Hard Disks (ch 2) - by Nicholas Majors


"Before we consider how to install, configure and maintain hard drives, we need a basic understanding of drive construction and design concepts. This chapter examines in some detail the parts and functional components of hard drive subsystems."

CD-ROM Drives:


CD-ROM Technical Summary - by Andy Poggio


"This summary describes how information is encoded on Compact Disc (CD) beginning with the physical pits and going up through higher levels of data encoding to the structured multimedia information that is possible with programs like HyperCard. This discussion is much broader than any single standards document, e.g. the CD-Audio Red Book, while omitting much of the detail needed only by drive manufacturers."

Microsoft MS-DOS CD-ROM Extensions 2.1 - by Microsoft Corp.


"The Microsoft MS-DOS CD-ROM Extensions are an extension to the MS-DOS operating system which permit reading CD-ROM disks which conform to both the High Sierra May 28th format and the ISO-9660 version of the High Sierra format. The CD-ROM disc appears just like a magnetic disk to the user and to applications software, ensuring compatibility with current software."

CD-ROM programming FAQ Version 1.0 - by Marcus W. Johnson


This document describes how to control a CD-ROM drive under DOS with the MSCDEX driver.

Information Specification for Bootable CD-ROMs - by SFF Committee


"This document defines how CD-ROM manufacturers can package several floppy and hard disk images on a single piece of media with the ability to catalog these images and selectively boot from any single image."

Floppy Drives:


Floppy Drive Controller Data Sheet - by Intel Corp


This is the official datasheet from Intel for the 82077AA single chip floppy disk controller chip.

The 8272A Floppy Disk Controller


This document details the IO port interface exposed by the common 8272A Floppy controller. Virtually every PC has one of this in it, virtually every OS supports em...

Calculating Serial Numbers for Floppy's - by 'Ray'


This is a short document that describes how DOS assigns volume serial numbers when formatting disks...

Floppy Media Type ID's - by Raster


Listing of the BIOS media ID codes for various floppy drive types and sizes.

Misc Topics:


Device Bay Specification v0.90 - by Compaq, Intel & Microsoft


"Device Bay is an industry specification defining a mechanism for easily adding and upgrading PC peripheral devices without opening the chassis. The Device Bay specification applies to all classes of computers, explicitly including desktop, mobile, home and server computers. This specification defines characteristics of both peripheral devices and system bays."

Media Status Notification Support Spec for SCSI and ATAPI Devices v0.1 - by Microsoft Corp.


"A major shortcoming of removable media devices on PC platforms is their inability to report to the host when the user attempts to eject the medium. Currently most removable media devices just eject the medium when the user presses the Eject button, and potentially any data the operating system has not saved to the device is lost. Various volume tracking and locking schemes reduce this risk, but do not eliminate it. Ideally, devices will have a means of communicating to the host that the user wants to eject the medium or has inserted a new medium.

This specification defines a protocol for providing this function for SCSI ATA and ATAPI devices. The support is enabled using a new SCSI command, ENABLE MEDIA STATUS, and the media status is retrieved using a new SCSI ATA command, GET MEDIA STATUS."

Converting between DOS and Physical Sector ID's - by Don Krull


This email message describes how to convert a DOS sector number into a BIOS sector number, taking into account the geometry of the disk.

Secure Deletion of Data from Magnetic and Solid-State Memory - by Peter Gutmann


"With the use of increasingly sophisticated encryption systems, an attacker wishing to gain access to sensitive data is forced to look elsewhere for information. One avenue of attack is the recovery of supposedly erased data from magnetic media or random-access memory. This paper covers some of the methods available to recover erased data and presents schemes to make this recovery significantly more difficult." - Paper includes many references.

The Design of Large-Scale, Do-It-Yourself RAIDs - by Satoshi Asami, Nisha Talagala, Thomas Anderson, Ken Lutz, and David Patterson


"In this paper we explore the design of 'Do-It-Yourself' RAIDs: RAID systems that can assembled by the end user from commercially available disks, enclosures, cables, racks, computers, and networks. We quantitatively evaluate the tradeoffs in cost, performance, and reliability of these DIY-RAID systems."

(new!) sections have been updated in the last week... (recent) sections have been updated in the last two weeks...