Msg: Re: MS-Word 5.0 in vDos-lfn (timesync=off)

Hi Kari,

In order to answer your question, I decide to split the question into two parts: how the date/time works in vDos-lfn, and how a file written operation in vDos-lfn is different from VPC.

1: In original vDos, the internal date/time in vDos moves forward by synchronizing with the date/time of the host system all the time. In other words, if it does not synchronize with the host system date/time, then the internal vDos date/time will stop to change (i.e. remain static). So like original vDos, vDos-lfn will always synchronize the date/time with the host system in order for the internal date/time to move forward if you don't set TIMESYNC=OFF. On the other hand, if you set TIMESYNC=OFF in vDos-lfn, then vDos-lfn will simulate the clock movement by using an internal timer, so that you will notice that the date/time does move forward in vDos-lfn even if you disable the time synchronization with the host system. Therefore, the implementation of TIMESYNC=OFF is not straightforward as it may seem at first glance.

2. Unlike Virtual PC, which maintains its own file system, vDos(-lfn) simply maps to a drive or directory in the host system for its file operations. In VPC, file operations are usually done in disk images (e.g. .VHD, .IMG or .FLP) instead of writing to the real file system of host machine, and even if the file is written into some real directory of the host machine it will still maintain its own file system, so VPC will set the file date/time according to its own internal date/time. On the other hand, since vDos(-lfn) simply maps to a host drive or directory, file operations in vDos(-lfn) will be transferred to the host system which will complete the tasks, so the date/time of a file will be set according to the date/time on the host system instead of the internal vDos-lfn date/time. However, file date/time setting functions are available in vDos-lfn (but not in original vDos) via Int21/AX=7143 (an LFN API), so a program can still set the date/time of a file or directory by calling this API inside vDos-lfn if it wants to.

Wengier

On Saturday, May 21, 2016 5:31 AM, Kari Eveli wrote:

Hello Wengier,

The timesync=off feature is a milestone for MS-Word 5.0 users. Back in
the 1990's, I used to use MS-Word and NB3 in tandem, there were tasks
that were much easier to accomplish with Xy-based programs like NB3,
e.g. search and replace, editing of formatting commands, total control
of file contents, and then there were tasks that were easier with
MS-Word, like columnar editing, certain search-and-replace situations
with paragraph endings included, and keyboard macros.

It seems that this really works. The MS-Word 5.0 Y2K bug involves saves
of formatted documents that are broken by the internal date formatting
of the MS-Word document retrieval system. Now, when I have a date of Jan
1, 1980 set in vDos-lfn, it is recorded in the document file summary,
and MS-Word documents are ok. Normally, if the date recorded is beyond
2000, there is field overflow in the file format, and the program
crashes if this kind of saved document is reloaded. But there is more,
it appears that the file is written with current real creation and
modification dates, which makes this unproblematic for the host system.
This is different of what happens in VirtualPC 2007 where the dates
written to disk are the pre-Y2K dates. Wengier, could you explain a bit
about the technical details of the date handling in this case?

P.S. Why Word 5.0, and not the freely available 5.5 DOS version with
Windows-type menus (and without the Y2K bug)? Word 5.0 retains the old
"Transfer, load" menus and other functionality that users of 1980s' DOS
Word still remember and cherish. DOS Word 2 was my first word processor,
I discovered XyWrite products much later!

Truly great! Thank you.

Best regards,

Kari Eveli
LEXITEC Book Publishing (Finland)
lexitec@xxxxxxxx

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18.5.2016, 22:30, Wengier W (Redacted sender wengierwu for DMARC) wrote:
> Hi Kari,
>
> I have added the feature to disable date/time synchronization in
> vDos-lfn so that it can maintain its own local date and time different
> from the system date/time. You can achieve this by setting
> "TIMESYNC=OFF" in config.txt. After that, you will able to change the
> vDos-lfn date/time by using the standard DATE and TIME command in
> vDos-lfn. As usual, I have updated the vDos-lfn binary and installer.
> Please download the new version.
>
> Wengier
>