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Networking I.P.B. 2029 1st June 1990 (JK)
Department Category Implementation
Network Software Advisory
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Windows 3 and Networks

Microsoft have just announced the release of their new version of Windows. Windows 3 is a significant improvement over the current Windows/2 and Windows 386 products in two major areas.

Firstly the user interface has been greatly improved and is now totally competitive with the other Graphical User Interfaces such as the Apple MAC user interface. Windows 3 can now truly be considered as the user interface to DOS, something which could never be said of Windows/2. There are now very few circumstances where a user will need to leave Windows 3 to perform a specific task.

Secondly, and perhaps most importantly, memory management has been vastly improved. This has been done by making use of the memory management and segment protection features of the Intel 80286 and 80386 processors. In implementing this enhanced functionality, Microsoft have however introduced an incompatibility with Windows/2. Any application which makes assumptions about real memory addresses will only work in 'Real Mode'. Microsoft have also changed the way in which DMA devices (such as the Apricot on-board Ethernet interface) are supported. Windows 3 has three modes of operation:

(If you just type WIN at the DOS prompt, Windows 3 will automatically determine the best mode of operation for your machine. The mode selected can be displayed by selecting Help About from the Program Manager screen.)

1) Real Mode (WIN /R) provides compatibility with previous versions of Windows for applications which have not been modified to run cleanly under Windows 3. It is also the ONLY mode which supports machines with less than 1MByte of memory or machines which have an Intel 8088 or 8086 processor.

2) Standard Mode (WIN /S) is designed for machines that have an Intel 80286 (or higher) processor and greater than 1MByte of memory. Segment swapping ensures that efficient use is made of extended memory, allowing multiple applications to be loaded simultaneously. This form of memory management is similar to that supported by OS/2.

3) Enhanced Mode (WIN /3) requires an Intel 80386 (or higher) processor and more than 2 MBytes of memory (although we would recommend a minimum of 4MBytes). This mode makes use of the virtual memory support of the 80386 processor to implement demand paging. This form of memory management is similar to that supported by UNIX, VMS and other advanced operating systems.

The implications for Apricot's On-board Ethernet drivers for VX-Net, Novell, and LAN Manager are therefore as follows.....

The current drivers will fully support both '/R' and '/S' modes of operation ('REAL' and 'STANDARD'). New drivers are being developed by Apricot to support '/3' mode (ENHANCED) and will be available as beta releases shortly (see below for timescales). Until these drivers are available, Apricot's customers will be able to derive all of the benefits of the Windows 3 user interface, and most of the benefits of Windows 3's enhanced memory management, by using the '/S' mode (STANDARD).

There are other problems relating to the use of Windows 3 on networks however, and these problems are network stack/shell dependent rather than LAN driver dependent.

In terms of the three network types that Apricot deal with, the situation regarding driver and stack/shell availability is as follows......

1) VX-Net

All releases of VX-Net up to and including VX-Net 3.13 will NOT correctly support Windows 3 in '/3' mode.

There will be a new release of VX-Net (Release 3.14) supplied by Apricot around the end of July/beginning of August that will have amongst other enhancements FULL Windows 3 support in the network stack, along with new On-board Ethernet drivers.

As with past versions, an upgrade path will be available, and full details will be announced nearer the time.

2) Novell

Novell themselves have just issued an upgrade pack that will allow the use of Windows 3 on their networks. The pack consists of a number of updated utilities both for the network user (new FLAG.EXE, LOGIN.EXE, GRANT.EXE, FILER.EXE and so on), new files for the SHGEN utility (shell generation), and a number of updated network adapter object files (for those cards where Novell themselves write the drivers). This upgrade will allow the use of Windows 3 in '/R' or '/S' modes without any Apricot On-board Ethernet driver updates (assuming you are currently using Vr 1.03 of the on-board Ethernet workstation drivers).

There will also be new object code files for the Apricot on- board Ethernet adapter to allow the correct use of the '/3' mode. These driver files will be available on beta within two weeks, and will be released in about six weeks.

Users who want to run Novell and Windows 3 will therefore need both the Novell upgrade pack (from their Novell supplier) to use Windows 3 in 'R' or '/S' modes, and the new network drivers (from us) if they wish to use '/3' mode.

3) LAN Manager

The drivers for the Apricot on-board Ethernet adapter are being updated to support Windows 3 '/3' mode. Beta versions should be available in two weeks, with final release currently scheduled for six weeks (same as the Novell on-board Ethernet drivers). The network software itself should not need changing. The current drivers (Vr 1.0.1) should support Windows 3 in '/R' and '/S' modes.

Full details of availability and final release dates will be published in another IPB as soon as those details are available.

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