Hardware Reference
In-Depth Information
turers. A third major producer of BIOS software, Award Software, is owned by Phoenix
Technologies, which continues to sell Award BIOS-based products.
After the motherboard hardware and BIOS of the IBM PC were duplicated, all that was
necessary to produce a fully IBM-compatible system was MS-DOS. Reverse-engineering
DOS, even with the clean-room approach, seemed to be a daunting task at the time, be-
cause DOS is much larger than the BIOS and consists of many more programs and func-
tions. Also, the OS has evolved and changed more often than the BIOS, which by com-
parison has remained relatively constant. This means that the only way to get DOS on an
IBM compatible back in the early 1980s was to license it. This is where Microsoft came
in. Because IBM (who hired Microsoft to write DOS in the first place) did not ensure that
its license agreement with Microsoft was exclusive, Microsoft was free to sell the same
DOS it designed for IBM to anybody else who wanted it. With a licensed copy of MS-
DOS, the last piece was in place and the floodgates were open for IBM-compatible sys-
tems to be produced whether IBM liked it or not.
Note
MS-DOS was eventually cloned, the first of which was DR-DOS, released by Digital Re-
search (developers of CP/M) in 1988. By all rights, DR-DOS was more than just a clone; it
had many features not found in MS-DOS at the time, inspiring Microsoft to add similar fea-
tures in future MS-DOS versions as well. In 1991, Novell acquired DR-DOS, followed by
Caldera in 1996 (who released a version of the source code under an open-source license),
followed by Lineo in 1998, and finally by DRDOS (
www.drdos.com
) in 2002.
Freeandopen-sourceDOSversionshavebeenindependentlyproduced,upgraded,andmain-
tained by the DR-DOS/OpenDOS Enhancement Project (
www.drdosprojects.de
) as well as
the FreeDOS Project (
www.freedos.org
)
.
Note
From 1996 to 1997, an effort was made by the more liberated thinkers at Apple to license
itsBIOS/OScombination,andseveralMac-compatible machinesweredeveloped,produced,
and sold. Companies such as Sony, Power Computing, Radius, and even Motorola invested
millions of dollars in developing these systems, but shortly after these first Mac clones were
sold, Apple canceled the licensing! By canceling these licenses, Apple virtually guaranteed
that its systems would not be competitive with Windows-based PCs. Along with its smal-
ler market share come much higher system costs, fewer available software applications, and
fewer options for hardware repair, replacement, and upgrades as compared to PCs. The pro-
prietary form factors also ensure that major components such as motherboards, power sup-
plies, and cases are available only from Apple at very high prices, making out-of-warranty
repair, replacement, and upgrades of these components not cost effective.
