Extract old DOS "database" data via parallel printer port?


I have won a new customer :-)

He has 5500 customer records on an old DOS based system.  This system appear to have no export capabilities of it's own.  There are data files and customer details are visible as text within them (when opened with Wordpad) but they are very messy files and may be binary files.  I have cracked one of these before but it was a terrible job that took many days.

The one thing the old application can do is print.  Any ideas to "capture" the output stream (which I can send to a parallel port but not to a file).  Note that I cannot print to serial.  I have only the choice of a printer driver (HP LaserJet is on the list) and LPT1, LPT2 or LPT3.

I guess what I want is a program which runs on a second PC which makes the PC pretend it is a HP Laserjet.  I then connect two PCs together (laplink cable) and print using the DOS application.  I then want the other PC to pretend it is a PCL Laserjet and then write the output as a text file.

Alternatively, a software application which intercepted the real LPT1 hardware and did the same would be fine as well.  

You can reach me at chris@timeboxsolutions.co.uk if you need more info.



Chris Van Buren  
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I do not know of anything that can do what you are describing.  However I have been in you situation many times.  Here are a few things to try.

I have worked with a lot of DOS Databases in the past.  The thing that I would do is try to actually get to the data in the files itself.  The garbage you are seeing is most likely binary data like you think.  These are pretty easy to convert from binary to ASCII.  The most difficult part will be determining the schema of the database.

If you know what kind of database the program is using ODBC may be a great option as well.

You may also want to look and see is the software can save the reports as text files.  I have worked with a lot of these old DOS programs and most have this ability.

If you send me more details on the data and/or database I may be able to give you more specific tips.
You may also want to try and open the files up in Excel.  Dbase and Paradox, 2 very common DOS databases will open up in Excel pretty clean.  Send me the extension of the database files and that may tell me exactly what kind of database is being used.
Daniel Van Der WerkenIndependent ConsultantCommented:
If you can install the Generic Text printer driver, you should be able to select a check-box that allows you to print to a file.

What operating system are you usnig on the system with the old datafiles?  Simply DOS or is it Windows 3.1 on top of DOS?

Like I said, install the Generic Text printer and use that to print to a file.  I'm pretty sure you can in Windows 3.x.
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Take a look at this, http://www.imeg.com/jadtech/c100spec.htm , it may be what you are looking for.

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Maybe it is a good idea to hook the disk drive up as slave on the ide cable on to a modern system, and copying the needed data over; that way, you would already have a backup of it, and a fast system to try all kinda things .
TimeboxAuthor Commented:
Thanks to all for the useful information.  FYI, the DOS application is running successfully in a command box under Win XP.

I think the text file option won't work in that this appears to be a real DOS application.  I see no choices except real LPT ports.  I can create a generic print driver and tell it to print to file but I cannot tell the DOS application to use that printer.  The DOS application can't print to any printer - only to LPT ports.

rshooper76 said:
>The garbage you are seeing is most likely binary data like you think.  
>These are pretty easy to convert from binary to ASCII.

That's very useful.   In the past I have tried some tools specific to the database I am using (FileMaker - the tools is called character sieve).  This improved things but did not give me a clean file.  I have now found some generic tools on the internet which look promising.  

I'm going to accept lidsky's answer in that he really did answer the question though I think I will go back to hacking the data files directly as the Jadtech device seems to be $800.



Chris Van Buren
TimeboxAuthor Commented:

I have achieved success with http://www.geocities.com/dosprint/ and the print2file utility also located there.

I will go now and give him his $40!

This has produced a very good result.  Hacking into the data files themselves would have i) been MUCH harder ii) given me much less data.  I haven't had to worry about data structure here.  I have all the data per customer and haven't had to fish into all the files.

Hope this helps somebody else someday.


Chris Van Buren
Found another possible solution, and it appears to be free.


Scroll down till you get to prn2fil3.zip -
TimeboxAuthor Commented:
One more comment to what I found:

The author of DOS PRINT says:
>DOS PRINT very good with file sharing and large files. You should use the
>prindir9 utility

I succeeded with DOS Print.  The whole process was not easy and I had good support from DOS Print so I am happy to recommend it.


There was still a lot of trial and error so don't give up!


Chris Van Buren
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