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Windows 95 (Win95) is great! Running on a Pentium 90 MHz computer with 16 Mb of
RAM, it's much faster than Windows 3.11 (Win311) and Windows for Workgroups 3.11
(WFWG3.11).
Some of the improvements in Win95 are:
•fully integrated 32-bit protected-mode operating system, eliminating the need for a separate copy of DOS;
•preemptive multitasking and multithreading support improving system responsiveness and smooth background processing;
•32-bit installable file systems including VFAT, CDFS, and network redirectors providing better performance, use of long filenames, and an open architecture supporting future growth;
•32-bit device drivers available throughout the system, delivering improved performance and intelligent memory use complete 32-bit kernel, including memory management, scheduler, and process management; and
•improved system-wide robustness and cleanup after and application ends or crashes, delivering a more stable and reliable operating environment more dynamic environment configuration reducing the need for users to tweak their system; and improved system capacity, including better system resource limits to address issues of Win311 users encountered when running multiple applications.
It allows preemptive multitasking for Win32-based applications. Unlike Windows 3.x, which used cooperative multitasking for Win16-based applications, Win32 programs do not need to yield to other tasks. Win32 applications use multithreading to improve performance and allow multiple programs to operate concurrently.
To support a higher level of memory protection for running DOS-based applications, Win95 includes a "global memory protection" attribute that allows the DOS system area to be protected from errant DOS-based applications.
When the global memory protection attribute is set, the DOS system area sections are read-protected so that applications can't write into this memory area and corrupt DOS support and DOS-based device drivers.
By default, Win95 runs DOS-based applications in a window, and enables the background execution setting, allowing the application to continue to run when it is not the active application.
Floppy Diskette Access
Floppy disk and multitasking performance is improved in Win95. Performance is not degraded when accessing floppy diskettes as under Win3.11
Disk Cache
VCACHE, a 32-bit protected-mode cache driver, in conjunction with the 32-bit VFAT, replaces the 16-bit realmode SmartDrive disk cache software provided with DOS and Win3.11
The VCACHE driver features a more intelligent caching algorithm than SmartDrive to cache information read from or written to a disk drive, and results in improved performance for reading information from cache.
Also, the VCACHE driver is responsible for managing the cache pool for the CD-ROM file System (CDFS), and the provided 32-bit network redirectors.
Another big improvement in VCACHE over SmartDrive is that the memory pool used for the cache is dynamic and is based on the amount of available free system memory. Users no longer need to statically allocate a block of memory to set aside as a disk cache, the system automatically allocates or deallocates memory used for the cache based on system use.
The performance of the system will also scale better than Win3.11 or WFWG3.11 due to the intelligent cache use.
CD-ROM Performance Improved
The 32-bit protected-mode CD-ROM file system "(CDFS) implemented in Windows 95 provides improved CD-ROM access performance over the real-mode MSCDEX driver in Win3.11 and is a full 32-bit ISO 9660 CD file system.
The CDFS driver replaces the 16-bit real-mode MSCDEX driver, and features 32-bit protected-mode caching of CD-ROM data. The CDFS driver cache is dynamic and shares the cache memory pool with the 32-bit VFAT driver, requiring no configuration or static allocation on the part of the user.
Specific benefits of the 32-bit CDFS driver:
•no conventional memory used replacement for the real-mode MSCDEX;
•improved performance over DOS-based MSCDEX and real-mode cache;
•better multitasking when accessing CD-ROM information no blocking; and
•dynamic cache support to provide a better balance between providing memory to run applications versus memory to serve as a disk cache.
Portions Copyright © 1995, Microsoft Corporation, All Rights Reserved
http://dgl.com/win95.html
updated July 7, 1995
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