16-Bit Windows Applications Backwards Compatibility: IBM OS/2 Warp
Better Than Microsoft Windows NT 3.5.  Windows NT 3.5 Uses Emulation to
Run 16-bit Windows Applications
 
 
OS/2 Warp has superior backward compatibility with 16-bit Windows
applications when compared to Windows NT 3.5.  The reason is that OS/2
Warp uses modified Microsoft Windows 3.1 code, which Microsoft licensed
to IBM as part of the 'divorce settlement' between the two companies,
to run 16-bit Windows application programs. On the other hand,
Windows NT 3.5 uses the Softwindows and SoftPC emulation technologies
from Insignia Solutions to run 16-bit Windows application programs.
This information has been excerpted from the article
"You Mean NT Can't Really Run Windows" in the May 15, 1994 issue of
Datamation, pages 67-68. It was also part of the March 1994 Microsoft
DevCast videoteleconference for developers.
 
The Datamation article notes the following detail information about the
Insignia Solutions' SoftPC and Softwindows technologies that Microsoft
licensed for Windows NT in a sidebar:
 
 '  When NT is running on RISC machines using Alpha, Mips, or SPARC
  chips, for example, Insignia code emulates both the Intel x86 chip
  and MS-DOS operating system, as well as all of the hardware and
  drivers that Windows and DOS expect to call upon.'
 '  On Intel-based PCs, there's no need to use Insignia to emulate the
  x86 chip, of course.  But Insignia still provides all of the
  Windows 3.1 and DOS drivers for the system hardware that make sure
  the 16-bit DOS and Windows applcations are isolated from direct
  contact with NT's protected Hardware Access Layer (HAL) or the
  hardware itself.'
 
Further on, the Datamation article provides more insights into the
development work done so that 16-bit Windows programs can run under
Windows NT 3.5:
 
 'Although Insignia's products play a crucial role in letting NT run
  16-bit Windows 3.1 apps, Microsoft's own developers worked long and
  hard on the bulk of the 16-bit Windows emulation code.  And they've
  kept on working long and hard of late to increase the speed at which
  the next version of NT (note: Windows NT 3.5) can run 16-bit Windows
  apps -- still, however, using Insignia's technologies.  Microsoft
  developed a concept called "Win16 on Win32 (WOW) to enable 16-bit
  Windows apps to run under NT, even emulating a few Windows 3.1 coding
  errors in the WOW layer so that all of the applications written to
  expect those errors would be able to run.'
 
The Datamation article notes that Insignia Solutions' technologies are
also used by other operating systems:
 
 'Insignia Solutions' SoftPC and Softwindows emulation products are
  generally used to run DOS and Windows 3.1 applications on RISC-based
  Unix workstations and Mac PowerPCs.  Insignia also sells a version of
  Softwindows for the Nextstep for Intel operating system.'
 
On the other hand, the Datamation article includes the following
information about OS/2's support of 16-bit Windows 3.x applications:
 
 '  Incidentally, it's been more than two years since five or six young
  programmers at IBM's Boca Raton labs figured out a way to run 16-bit
  Windows 3.x apps on IBM's then-new 32-bit OS/2 2.x OS in native
  mode.  And they pulled it off in less than three months.'
 
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Note: Most Windows NT users and enthusiasts will not say that Windows
NT 3.5 uses emulation to run 16-bit Windows application programs.
A few Windows NT 3.5 users and enthusiasts do refer to the 'Windows
Emulator' in Windows NT 3.5.  However, even these individuals do not
mention the use of Insignia Solutions' SoftPC and SoftWindows
technologies in the Windows NT WOW subsystem.  Some Windows NT users
and enthusiasts have labeled the Datamation article 'sensationalism'.
On the other hand, users and enthusiasts of OS/2 and other competitive
operating systems may consider the Datamation article to be
'an example of good investigative reporting'.