View Full Version : Parity check 2 error with a DOS program

June 2nd, 2008, 06:25 PM
I'm running a old dos app which after I try to print to LPT1 crashes the program and I get a error message of parity check 2. The autoexec.bat and config.sys are very minimal. IE the autoexec.bat only calls the dos app and the config.sys is buffers=41 files=124 Any ideas on where to go to try and fix this issue?

June 2nd, 2008, 08:01 PM
Parity errors are sometimes the result of a bad DMA transfer. Is your parallel port set up as regular, bi-directional, EPP, or ECP in the BIOS? If ECP, I would back it back down to EPP or lower (ECP is the only mode that uses DMA).

July 9th, 2008, 07:37 PM
Careful. One of the granddaddies of PC viruses was known as "Parity" and would sometimes show this behavior. See:


"PARITY CHECK 2" usually indicates an expansion memory error, but it doesn't need a memory card to produce it. You may want to try to isolate the cause by pulling any cards not needed for program execution and seeing if the problem persists.

There's always the possibility that it's also being caused by bad software.

July 12th, 2008, 07:29 PM
Usually, if there is a RAM problem the "PARITY CHECK 2" error will appear upon boot. If you watch closely a fraction of a second before this error a specific error code (sometimes to indicate which RAM chip is bad) will sometimes flash on the screen too.

To have a program report this error is fishy but maybe the program is using memory that does not get checked when the system boots. But that makes no sense.

I would check the software for viruses first.