;***************************************************************************** ; PROGRAM ----: NWBCAST.ASM, version 1.0 ; AUTHOR -----: Kevin E. Saffer, 904-296-9000 Days EST, 262-1020 Evenings ; COPYRIGHT --: None, placed into the public domain ; CREATED ----: 1/22/1994 at 13:04 ;***************************************************************************** ; Introduction: ; ------------- ; Implements a software interrupt service routine for the Novell shell ; versions 3.01 and above. The interrupt handler will insert a programmer ; specified keystroke into the PC's keyboard buffer whenever a broadcast ; message is detected. The Clipper application may then handle this event ; by defining a SET KEY procedure tied to the keystroke specified in the ; install routine. The Clipper procedure may then use the NETTO functions ; to handle the incoming message. ; ; Warning: This routine installs a ISR (interrupt service routine) which ; MUST be removed before program exit by calling the uninstall ; function. Leaving the ISR active after program completion will ; cause the computer to transfer control to an incorrect address ; the next time a broadcast message is detected. This will most ; likely result in a locked up PC. A future version can be built ; as a small TSR loaded before the Clipper application. This will ; allow the routine to remain in memory even if the Clipper pgm ; crashes. An interface module will be linked into the Clipper ; application to communicate with the TSR. After this release is ; debugged, I'll get to work on the TSR version. ; ; Since an ISR is used, this module may never be overlayed. The ISR code ; must always be available to handle the interrupt, therefore this object ; file must be placed into the root portion of your link script. It will ; only increase the load size of the application by 700 bytes. ; ; Compatibility: ; -------------- ; Netware shell versions 3.01 and above will issue an INT 2F whenever a ; broadcast message is waiting. For this reason, the latest shells must be ; used; they are available for downloading on the Compuserve NOVLIB forum. ; ; This routine will not work with the DOS extenders from CA or Blinker. The ; reason it will not work is that I have no idea how to switch these routines ; from segment addressing over to protected mode addressing. If anyone has ; this knowledge, please share it on the forum or call me directly. ; ; Usage Restrictions: ; ------------------- ; Should you wish to shell out of the Clipper application, this routine must ; be shut down using NB_STOP() prior to running other programs. If left ; active, any broadcast message will cause the specified keystroke to be ; fed into the shelled program. Re-start the routine using NB_START() when ; the Clipper application regains control. ; ; Messages Must Be Allowed! (CASTON) ; ---------------------------------- ; Before use, you should change the Netware shell's brodcast mode to 0 to ; allow normal broadcast message handling. This routine will then prevent ; the message from being displayed on the last display line. Use the NETTO ; function FN_SETBMOD( 0 ) to accomplish this, or ensure CASTON has been ; executed prior to loading your application. ; ; Compiling/Linking: ; ------------------ ; Compile with MASM 5.1 or greater using "MASM nwbcast;" ; Link the resulting NWBCAST.OBJ into your application at the root level. ; ;***************************************************************************** ; Clipper callable function list: ;***************************************************************************** ; ; NB_START( ) - installs the interrupt service routine with specified key ; NB_STOP() - removes the interrupt service routine ; NB_SERVER() - returns the connection ID of the server holding the last message ; ;***************************************************************************** .RADIX 16 ; my family has 8 fingers per hand so we think in HEX! ; declare callable routines as public PUBLIC NB_START ; installation routine PUBLIC NB_STOP ; uninstallation routine PUBLIC NB_SERVER ; last message server connection number ; declare clipper parameter routines EXTRN __PARC:FAR ; get character string, segment:offset in DX:AX EXTRN __PARCLEN:FAR ; get length of a string parameter into ax EXTRN __PARCSIZ:FAR ; get size of memory allocated for string parameter EXTRN __PARDS:FAR ; get date string, segment:offset in DX:AX EXTRN __PARINFA:FAR ; get size of array parameter or element type EXTRN __PARINFO:FAR ; get number of parameters or type of one EXTRN __PARL:FAR ; get logical, value in AX EXTRN __PARND:FAR ; get numeric double, segment:offset in DX:AX EXTRN __PARNI:FAR ; get numeric integer, value in AX EXTRN __PARNL:FAR ; get numeric long, value in DX:AX EXTRN __RETC:FAR ; return string, push seg:off onto stack EXTRN __RETCLEN:FAR ; return string of x length, push seg:off:length EXTRN __RETDS:FAR ; return date string, push seg:off onto stack EXTRN __RETL:FAR ; return logical, push 1 register onto stack EXTRN __RETND:FAR ; return double, push 4 registers onto stack EXTRN __RETNI:FAR ; return integer, push 1 register onto stack EXTRN __RETNL:FAR ; return long, push 2 registers onto stack ; define a keyboard buffer structure for the insertion routine BIOS_DATA SEGMENT AT 40 ORG 1A BUFFER_HEAD DW ? ; pointer to the keybord buffer head BUFFER_TAIL DW ? ; pointer to the keyboard buffer tail ORG 80 BUFFER_START DW ? ; starting keyboard buffer address BUFFER_END DW ? ; ending keyboard buffer address BIOS_DATA ENDS ; declare our code segment CODE SEGMENT 'CODE' ASSUME CS:CODE,DS:CODE ; inform MASM of our intentions OLDINTSEG DW 0 ; old 2F vector segment OLDINTOFF DW 0 ; old 2F vector offset KEYCODE DW 1 ; keyboard scan code to be inserted (this is Ctrl-A) SERVERID DW 0 ; server connection number ;***************************************************************************** ; NB_START() - interrupt service routine installation ;***************************************************************************** NB_START PROC FAR PUSH BP ; save vital registers MOV BP,SP PUSH DS PUSH ES MOV AX,1 ; retrieve the keycode to be used PUSH AX CALL __PARNI MOV CS:KEYCODE,AX ; save it and restore the stack POP AX PUSH CS ; reset the data segment to point to our code segment POP DS CMP OLDINTSEG,0 ; check to see if the vector was already changed JZ NB_START1 ; no, proceed with vector change POP ES ; restore clipper registers POP DS POP BP CLD ; reset the direction flag RET ; return to clipper NB_START1: MOV AX,352F ; get interrupt vector 2F into ES:BX INT 21 ; call dos MOV OLDINTSEG,ES ; save the existing handler segment MOV OLDINTOFF,BX ; save the existing handler offset MOV WORD PTR [INTADDR+2],ES ; update ISR with existing segment MOV WORD PTR [INTADDR],BX ; update ISR with existing offset PUSH CS ; store the segment of new routine POP DS ; and place it into DS MOV DX,OFFSET NB_INT2F ; offset of the new routine to DX MOV AX,252F ; set interrupt vector 2F from DS:DX INT 21 ; call dos POP ES ; restore clipper registers POP DS POP BP CLD ; reset the direction flag RET ; return to clipper NB_START ENDP ;***************************************************************************** ; NB_STOP() - interrupt service routine uninstallation ;***************************************************************************** NB_STOP PROC FAR PUSH BP ; save vital registers MOV BP,SP PUSH DS PUSH ES PUSH CS ; reset the data segment to point to our code segment POP DS CMP OLDINTSEG,0 ; check to see if the vector had been changed JZ NB_STOP2 ; no, return to clipper MOV AX,OLDINTSEG ; retrieve old routine segment MOV DX,OLDINTOFF ; retrieve old routine offset PUSH AX ; store the segment of old routine POP DS ; and place it into DS MOV AX,252F ; set interrupt vector 2F from DS:DX INT 21 ; call dos MOV OLDINTSEG,0 ; clear the existing handler segment MOV OLDINTOFF,0 ; clear the existing handler offset NB_STOP2: POP ES ; restore clipper registers POP DS POP BP CLD ; reset the direction flag RET ; return to clipper NB_STOP ENDP ;***************************************************************************** ; NB_SERVER() - return the connection ID of the server holding the message ;***************************************************************************** NB_SERVER PROC FAR PUSH BP ; save vital registers MOV BP,SP PUSH DS PUSH ES MOV AX,CS:SERVERID ; retrieve the connection number PUSH AX CALL __RETNI POP AX POP ES ; restore clipper registers POP DS POP BP CLD ; reset the direction flag RET ; return to clipper NB_SERVER ENDP ;***************************************************************************** ; NB_INT2F - interrupt service routine ;***************************************************************************** NB_INT2F PROC NEAR PUSHF ; save calller's flags for the original interrupt 2F CMP AX,7A85 ; is a broadcast message is waiting? JE NB_INT2F1 ; yes, take over the interrupt JMP NB_INT2F4 ; no, transfer control to the original interrupt NB_INT2F1: PUSH AX ; save the registers used by this routine PUSH BX PUSH DX PUSH DS PUSH CS ; set DS to this segment POP DS CLD ; clear direction flag MOV CS:SERVERID,CX ; save the server connection number for later XOR CX,CX ; inform Netware we will handle the message MOV BX,BIOS_DATA ; point ds to the bios data area MOV DS,BX ASSUME DS:BIOS_DATA ; inform MASM of the new data segment CLI ; disable interrupts for buffer manipulation MOV BX,BUFFER_TAIL ; get buffer tail address MOV DX,BX ; transfer it to DX ADD DX,2 ; calculate next buffer position CMP DX,BUFFER_END ; did we overshoot the end? JNE NB_INT2F2 ; no, then continue MOV DX,BUFFER_START ; yes, then wrap to start of buffer NB_INT2F2: CMP DX,BUFFER_HEAD ; is the buffer full? JE NB_INT2F3 ; yes, then end now MOV AX,CS:KEYCODE ; retrieve the keycode MOV [BX],AX ; insert the keycode into the keyboard buffer MOV BX,DX ; advance the tail MOV BUFFER_TAIL,BX ; record its new position NB_INT2F3: STI ; enable interrupts POP DS ; restore registers POP DX POP BX POP AX NB_INT2F4: POPF ; restore the caller's flags DB 0EAH ; JMP FAR immediate opcode INTADDR DD 0 ; original int 2F address, updated by NB_START() NB_INT2F ENDP CODE ENDS ; end of segment END ; end of program