Microsoft Starts Offering ROM-Executable DOS
 
Microbytes Daily News Service
Copyright (c) 1989, McGraw-Hill, Inc.
Microsoft has announced availability of a version of MS-DOS that
executes in your computer's ROM rather than its RAM. The
ROM-executable DOS is aimed at makers of laptop computers and
embedded systems. The first OEM licensee is Poqet Computer, which
will use ROM MS-DOS in its Poqet PC, announced last month.
 
Microsoft's ROM-executable MS-DOS differs from versions of DOS
that reside in ROM but are then loaded into RAM (as in some Tandy
machines). The Microsoft version executes directly in ROM.
 
The main advantage of ROM-executable DOS is that it saves
approximately 40K bytes of RAM, which is then available for other
applications. For embedded systems, the ROM version can be built
directly into the hardware so that MS-DOS applications can run in
the embedded system. The ability to build MS-DOS into embedded
applications will make it easier to develop software for those
systems, according to Microsoft product manager Mark Chestnut.
ROM-executable DOS is "preconfigured" in the host computer
system, thus eliminating boot procedures off disk or time delays
while the operating system loads into RAM.
 
Microsoft had to significantly rewrite MS-DOS to make it
ROM-executable, program manager Tom Lennon told Microbytes Daily.
"We had to completely reorganize the segmentation areas in
memory," said Lennon. The ROM version is actually a "split
system," using small portions of RAM for accessing "modifiable"
data such as the file structure and certain device drivers, he
said.
 
Microsoft will supply a "binary adaptation kit" to OEM licensees,
which includes the code and instructions necessary for "burning
in" MS-DOS into the OEM's ROM chips. Emerson Radio Corp. and
Headstart Technologies have licensed the product from Microsoft.
Vadem Corp. will distribute ROM DOS for its Intel 80186-based
embedded processor systems.
 
Microsoft has no plans for ROMable Windows. "There are some
problems with ROM execution on more complex applications," said
Lennon. ROMs are slower than high-speed RAMs, for one thing, and
"there's not a lot of room for extra ROMs in PC architectures,"
he said.
 
Contact: Microsoft, 16011 NE 36th Way, Box 97017, Redmond, WA
98073; (206) 882-8080.
 
                              --- Nick Baran
 
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