Browse Prior Art Database

Multiple DOS Levels Per Fixed Disk

IP.com Disclosure Number: IPCOM000039754D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 4 page(s) / 17K

Publishing Venue

IBM

Related People

Dachowski, RP: AUTHOR [+3]

Abstract

In the past, only ONE level of DOS per fixed disk was possible. This restriction forced the DOS customer to allocate his ENTIRE fixed disk to ONE level of DOS. A method is described which allows the user to partition his fixed disk into a maximum of FOUR bootable DOS partitions. In the past, it was possible to allocate the storage of a fixed disk on an IBM personal computer (PC) system into 4 distinct, logical partitions. Although 4 partitions could be defined, ONLY 1 partition could be formatted as a DOS partition. As a result, there was no way to create a fixed disk with more than 1 bootable DOS level on it. This restriction forced the user to completely reformat his fixed disk if he desired to install the new level of DOS on it.

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This is the abbreviated version, containing approximately 37% of the total text.

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Multiple DOS Levels Per Fixed Disk

In the past, only ONE level of DOS per fixed disk was possible.

This restriction forced the DOS customer to allocate his ENTIRE fixed disk to ONE level of DOS. A method is described which allows the user to partition his fixed disk into a maximum of FOUR bootable DOS partitions. In the past, it was possible to allocate the storage of a fixed disk on an IBM personal computer (PC) system into 4 distinct, logical partitions. Although 4 partitions could be defined, ONLY 1 partition could be formatted as a DOS partition. As a result, there was no way to create a fixed disk with more than 1 bootable DOS level on it. This restriction forced the user to completely reformat his fixed disk if he desired to install the new level of DOS on it. In accordance with the new method, it is possible to store up to 4 bootable levels of DOS on a single fixed disk. The space for each partition is still defined by using the FDISK and FORMAT programs that are provided on the DOS program diskette. However, the method is composed of the UNIQUE programs that allow the user to initially configure the fixed disk into up to 4 bootable DOS partitions (with each partition containing a different level of DOS) and to switch between the bootable DOS partitions. An overview of this method is as follows: 1. The user must IPL the IBM PC which contains the fixed disk to

be formatted.

2. The user must execute the DOS command file, named HFINIT.BAT, and follow the instructions that appear on the screen.

3. Once the command file has been successfully executed, the user

executes the program, ACTPX, (where X = 1, 2, 3, 4), to acti

vate the desired partition of the fixed disk.

4. After the partition is activated, the IBM PC will boot the

level of DOS contained within it. This method requires an IBM PC (PC1, XT, AT, etc.), and levels 2.1 and above of the IBM Disk Operating System (DOS) software. This method is very useful in those software areas that need to run with multiple levels of DOS. It saves the user from having to perform the time-consuming process of reformatting his ENTIRE fixed disk before using a new level of DOS. Being able to run on multiple levels of DOS is a valuable advantage, since there are several popular levels of DOS in the marketplace today. Some examples of applicable software areas are given below: 1. in the development of new or existing software

2. in the testing of new or existing software

3. in the use of software programs where several of these soft

ware programs ONLY work, or work BEST with, a particular level

of DOS The details of the basic operation of this method are as follows:

1. The user must IPL the IBM PC which contains the fixed disk

that is to be split up into multiple (up to 4) bootable DOS

partitions.

1

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2. The user must execute, in order, the programs, HFINIT,

HFINIT2, HFINIT3 and HFINIT4. During the execution of these

programs, instructions will be displayed on the screen which

will gu...