[comp.sys.ibm.pc.hardware] disable printer via software

ebergman@isis.cs.du.edu (Eric Bergman-Terrell) (02/17/91)

rather than shorting pins on the parallel port, i'd disable the printer
by patching the executable file - change "prn" to "nul".

"nul" is dos' null device - i.e. the bit-bucket, and is sometimes 
useful.  for example, if i want to make sure that a floppy is readable\
i do the following:

copy/v a:\*.* nul:


terrell

robl@idca.tds.PHILIPS.nl (R. Luursema) (02/21/91)

In article <1991Feb16.164617.11199@isis.cs.du.edu> ebergman@isis.UUCP (Eric Bergman-Terrell) writes:
>
>copy/v a:\*.* nul:

Why do you specify the /v (verify after write) flag with this copy?
Copy cannot verify data written to the null device, or any other character
device. The verify is a dummy read after write; data is not stored in memory
and not compared. 


Rob.
--
     _ _ 
    / U |         Rob Luursema, Philips Information Systems Apeldoorn 
   /__ <                         robl@idca.tds.philips.nl
  88  |_\     "The trouble with everyone is that they generalize too much"