Category : C Source Code
Archive   : FILTERS.ZIP
Filename : FECHO.ASM

 
Output of file : FECHO.ASM contained in archive : FILTERS.ZIP
Name fecho
Title
page ,132
comment /

This program is a filter that reads from standard input and
echoes both to standard out and standard error output. This
is useful when debugging filter sequences because it allows
you to view the intermediate data as the commands are executed.

/
;===================================================================
code segment public
;===================================================================
;
; command line is at 80h of psp - first byte is length
;
org 80h
parmsize db ?
parm db 7fh dup (?)
;
; .com starts at 100h - but must jump around any data area
;
org 100h ; com file starts here
assume cs:code,ds:code,es:code
fecho:
jmp clear
;===================================================================
;
; data area for .com programs
;
inchar db ?
;
;===================================================================
clear:
;
; start of actual code is here (clear)
;
;
; These two i/o parameters are constants.
;
lea dx,inchar ; offset of inchar
mov cx,1h ; get 1 character
again:
;
; read a character
;
xor bx,bx ; zero is handle of standard input
mov ah,3fh ; read a file/device function
int 21h ; invoke the function
;
; if carry set of ax=0 exit
;
jc oops ; i/o error
and ax,ax ; set flags
jz oops ; eof
;
; now output to standard output
;
output:
mov bx,1h ; standard output handle
mov ah,40h ; dx still points at inchar
int 21h ; call dos output function
;
; now output to error output as an echo
;
mov bx,2h ; standard output handle
mov ah,40h ; dx still points at inchar
int 21h ; call dos output function
jmp again ; repeat cycle
oops:
int 20h ; return to dos
code ends
end fecho


  3 Responses to “Category : C Source Code
Archive   : FILTERS.ZIP
Filename : FECHO.ASM

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/