Subj : futil.asm redeux
To   : Paul Williams
From : Jasen Betts
Date : Sat Sep 14 2002 08:34 am

Hi Paul.

12-Sep-02 00:00:50, Paul Williams wrote to BEN RITCHEY


 PW> Hi BEN RITCHEY, hope you are having a nice day

 PW> What I'd like to do is to be able to hit <right-shift><ctrl>R and
 PW> have RING< placed into the xmit buffer which would then be sent
 PW> out a comport where a program on another would see it and think it
 PW> came from a modem on that box. (well not just ring but any other
 PW> strings as well)

To do that you'll need to modify the keyboard watching code and the
buffer-stuffing code too.

what's it for anyway?

 something like this maybe...  most of my mods are marked with *


;       T H I S   I S   U N T E S T E D   C O D E
;     -----------------------------------------------


Int_9 PROC FAR

        assume DS:nothing,ES:nothing        ; Could (and will) be anywhere

        push AX                                ; Must preserve EVERY register
        push CX
        push DI
        push ES
        xor AX,AX
        mov ES,AX

        in AL,KBD_PORT                        ; Scan code of key pressed
        mov AH,ES:[SH_STATE]                ; Current shift state bits
        and AH,KUSED                        ; Mask out unused bits
        mov DI,offset KeyCodes                ; Scan key codes table
        mov CX,KEYS
@@:
        cmp AX,CS:[DI]
        je @Found1
        add DI,SZ_ka
        loop @B
                                        ; Key was not found

*       xor AX, LSHIFT or RSHIFT        ; swap shift bits..
*       mov DI,offset KeyCodes
*       mov CX,KEYS
*  @@:
*       cmp AX,CS:[DI]
*       je @Found2
*       add DI,SZ_ka
*       loop @B
                                             ;  still not found!
       pop ES                                ; Restore saved registers
       pop DI
       pop CX
       pop AX
       jmp CS:[kbdvec]                        ; Pass though to original vector

;
; Key combo found; take action
;

*@Found0:
        in AL,KBD_CTRL                        ; Save value of kbd control lines
        mov AH,AL
        or AL,80H                        ; Set kbd enable bit
        out KBD_CTRL,AL
        mov AL,AH
        out KBD_CTRL,AL
        mov AL,20H                ; Signal end of HW interrupt to 8259A
        out 20H,AL
*  ; don't push BX
        xor BX,BX
        mov CX,SZ_ka/2
        ret

*@found1:
*        PUsH BX
*        call @found0
        jmp SHORT @F
@Clp:
        mov AX,CS:[DI+BX]        ; Copy variables to intercept data area
        mov CS:[BX+offset cstate-2],AX
@@:
        inc BX
        inc BX
        loop @Clp

* :@Isrdone
        pop BX                                ; Restore registers
        pop ES
        pop DI
        pop CX
        pop AX
        iret


*@found2:
*        PUSH BX
*        call @found0

*   ;
*   ;  HMM, dunno what goes here...  the wedge seems to block all sending
*   ;  of characters.
*   ;

        jmp @isrdone;



 -=> Bye <=-

---
 * Origin: Green eggs and ham:  Environmentally sound produce. (3:640/531.42)

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