Again, working with old system, 64MB memory, DOS only. Ouch! The OS got corrupted somehow and it was not possible to redirect lpt1 to com1, using c:> mode lpt1=com1.
I had to backup all the data and reinstall the OS. Ouch! Where can I find DOS? Another thing is the bios was way outdated too. No PXE-Boot, no USB boot, no CD-ROM device,and broken floppy disk. Quaduple ouch!
After sometimes, I managed to install DOS and restore the data. It was time to run the application, and all I got was DOS Error 4. :(
To make the long story short, I got some good information from http://www.cms-track.com/Support/webhelp/html/idh_dos_error_4.htm
The solution is:
1. SET CLIPPER=F99 in autoexec.bat
2. In config.sys, put FILES= and BUFFERS=, where
The FILES= must be at least 61. (FILES=61)
The BUFFERS= must be at least 41. (BUFFERS=41)
No more old system please!!!