;
;CNTL-P.A86 - Toggles Printer Echo On And Off
;****************************************************************
;* Program to toggle the cntlp switch from within a SUBMIT file *
;* Dec. 10, 1982....CP/M-86, Version 1.1.                       *
;* To use, include this CMD file name as one of the lines in the*
;* .SUB file.  Each execution toggles the switch.               *
;* Create the object file by: ASM86 CNTL-P, then                *
;* GENCMD CNTL-P 8080.                                          *
;****************************************************************
;
   org     100h            ;8080 model
;
   mov     cl,31h          ;"Return SYSDATA Address" function
   int     224             ;BDOS function call
;
;****************************************************************
;* BDOS function 31h returns the segment in ES and the offset   *
;* in BX.  Byte number 22(d) from this offset is the list       *
;* toggle.  The following instruction changes the contents of   *
;* this byte to ffh from 00h, and vice-versa:                   *
;****************************************************************
;
   not     ES: byte ptr 22[bx]
;
;****************************************************************
;* The preceding three instructions may also be used at any     *
;* point in an applications program to echo subsequent console  *
;* output to the LST: device, and at a later point to disable   *
;* the echo.                                                    *
;****************************************************************

   mov     cl,00h          ;return to CP/M-86...
   mov     dl,00h          ;freeing memory
   int     224             ;BDOS function call
;
   END