interrupst

 BBS: Inland Empire Archive
Date: 03-19-92 (16:05)             Number: 182
From: MICHAEL MALLEY               Refer#: NONE
  To: TOM ROLLINS                   Recvd: NO  
Subj: interrupst                     Conf: (2) Quik_Bas

TR>Does anyone have a routine that uses dos to see whether at
TR>printer is connected and checks whether it is online or
TR>not? I would appreciate seeing the code if you have an

Regs.ax = &H200
Regs.dx = (0 - 2 for LPT1 - LPT3)
CALL Interrupt(&H17, Regs, Regs)

'Regs.ax returns the printer status in AH.

AH% = Regs.ax \ 256

7 6 5 4 3 2 1 0
              1  Timeout
          x x    Unused
        1        I/O error
      1          Printer selected
    1            Out of paper
  1              Acknowledged
1                Printer not busy

If you're using a Personal Computer AT, a PC XT 286, or a PS/2, and the
printer is busy, it will execute Int 15H function 90H, which is a device
wait.  My guess is that it will wait for a while to get ahold of the
printer.  But if you're printing something, the best thing to do is to
trap the error through BASIC, because someone can always reach over and
turn off the printer resulting in a crashed program.

 * SLMR 2.1a * My compiler has a first name, it's Q.U.I.C.K.

--- Maximus 2.01wb
 * Origin: UltraTech - Nashville, TN  (615) 356-0453 {HST} (1:116/30)