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diff --git a/reference/C/CONTRIB/SNIP/cbtrap.asm b/reference/C/CONTRIB/SNIP/cbtrap.asm
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+        PAGE ,132
+
+;  Install a custom Interrupt 1b (Ctrl-Break exception) handler
+;
+;  Public domain by Bob Stout
+;
+;  Requires MASM 5.1 or later or equivalent
+;
+;  Assemble with:       MASM /Mx /z ...
+;                       TASM /jMASM /mx /z ...
+
+%       .MODEL  memodel,C               ;Add model support via command
+                                        ;line macros, e.g.
+                                        ;MASM /Dmemodel=LARGE
+
+        .DATA?
+_origvec        dd      ?
+
+        .DATA
+
+        public  cbrcvd
+
+cbrcvd  dw      0
+
+        .CODE
+
+;
+;  This is our actual ISR
+;
+myint1b:
+        mov     ax,-1
+        mov     cbrcvd,ax
+        iret
+
+;
+;  Call this to install  our ISR
+;
+ins1b   PROC    USES AX BX DS ES
+        mov     ax,351bh                ;get old vector...
+        int     21h
+        mov     word PTR _origvec,bx
+        mov     word PTR _origvec+2,es  ;...and save it
+
+        push    cs                      ;get myint1b segment in DS
+        pop     ds
+        mov     dx, OFFSET myint1b      ;install myint1b in int 1bh
+        mov     ax,251bh
+        int     21h
+        ret
+ins1b   ENDP
+
+;
+;  Call this to uninstall our ISR
+;
+redo1b  PROC    USES AX BX DS
+        mov     dx, word PTR _origvec   ;restore original vector
+        mov     ds, word PTR _origvec+2
+        mov     ax,251bh
+        int     21h
+        ret
+redo1b  ENDP
+
+        end