VNC and Windows 95

HELP! Small Business Solutions helpsbs "at"
Tue, 01 Aug 2000 02:39:21 +0000


I'm not sure of the inner workings of VNC nor am I a Win95 programming
genius but I assume VNC is a 32-bit app which must be run in protected mode
for Win95.

Some snippets from the Windows 95 Resource Kit manual:

pp. 139 on 'Shared Installations' -- "... the first access to the network
must occur in real mode. For shared installations that use a Windows 95
protected-mode network client, Microsoft real-mode networking (NET.EXE) is
used for the first network connection, even for connecting to a NetWare
network." <some sentences omitted> "Real mode versions of NetBEUI and
IPX/SPX-compatible protocols are built into NET.EXE. Real-mode networking
includes only the basic redirector, there is no support for mailslots or
named pipes. Microsoft TCP/IP cannot be used until after the system loads
and switches to protected mode."

pp. 258 on 'Starting the Network During System Startup' -- "If your
computer uses any real-mode components for the client, protocol, or network
adapter, then you must include commands to start the network in
AUTOEXEC.BAT or a batch file that is called from AUTOEXEC.BAT."

This is what it means to me (of course, I could be very mistaken, as
usual). If VNC is a 32-bit protected mode app, it cannot be loaded until
the processor is switched to protected mode and the protected mode portion
of the operating system is loaded regardless if it is a service or started
from the command shell or startup folder. I'm assuming that the startup
sequence is the same both for a shared installation (client-server type)
and for a standalone or peer-to-peer network (the Resource Kit manual is
not specific), then it make sense that the protected mode portion be loaded
after a user logs in for the first time. This way the correct
services/apps/protocols/etc. can be loaded for the configuration associated
with that user. Also, if only the basic redirector is loaded prior to
switching to protected mode, then all your network services (TCP/IP
especially) are not available to you.

I'm assuming Microsoft made some changes in the startup sequence since I
haven't noticed any Win 98/NTWS users chime in with this problem.

So what is the fix? As far as I can tell, you would have to load a
real-mode stack and any other required components in AUTOEXEC.BAT so that
they start on initial bootup. Then I'm guessing VNC should be able to see
the login screen. The downside is that these real-mode drivers are _not_
removed from memory once protected-mode networking components are loaded.
So why doesn't this affect the display on a reboot? I'm guessing that the
protected-mode drivers are not completely unloaded on reboot since they
successfully loaded on initial boot. Don't know for sure, I can't find
anything in the Resource Kit.

I really don't have time to test my theories but maybe someone else would.

FWIW, hope this helps at least clarify some things.


Ed Schaperjahn
HELP! Small Business Solutions


At 09:13 PM 7/29/00 +0200, you wrote:
>>      Thanks - I appreciate the response.  I, too, installed the VNC
>>service on the Win95 machine using the "Administrative Tools" menu,
>>and set the password after rebooting the workstation.  I have also
>>tried connecting to the Win95 server using both the VNC viewer
>>(trying both the host name and the explicit IP address & port #)
>>and the browser-based Java viewer, but can't connect while the
>>PC is not signed on.  I am able to PING the PC successfully.
>>      I'm guessing there is something on the Win95 side of things
>>which is preventing the VNC service from getting started after bootup.
>>Do you have the PC setup to logon to a Win-NT domain? or workgroup?
>>How do you connect to the Win95 server...from Win-NT?  using VNC
>>viewer or a browser?  As you can tell, I'm scraping for any clues
>>which may help.

>Strange, it works at most WIn95 and Win98 PC's I have at work.
>I can connect without a problem from a Mac (MacOS 9.04), Linux 
>(RedHat 6.2) and WinNT ws 4.0.
>Are you trying with <hostname>:0 or <hostname>:5900 ?
>The last one doesn't work.


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