better MONITOR -> DOS Wedge integration

src/basic/wedge/wedge_dos.s

@@ -471,6 +471,7 @@ wedge_dos_wrapper_error_common:
 	; Print error - within the MONITOR
 
 	jsr do_error_print_only
+	jsr print_return
 	bra wedge_dos_wrapper_exit_nocheck
 
 wedge_dos_SYNTAX_error:

src/mon_m65/bsmon.s

@@ -1599,9 +1599,25 @@ Print_BCD:
 Mon_DOS:
 ; ******
 
-         JSR  Print_CR
+; Shift BUF content so that '@' is first character
+
+@lp1     LDA  BUF
+         CMP  #'@'
+         BEQ  @wedge
+         LDX  #01
+@lp2     LDA  BUF,x
+         DEX
+         STA  BUF,x
+         INX
+         INX
+         CPX  #80
+         BNE  @lp2
+         BRA  @lp1
+
+; Launch DOS Wedge
+
+@wedge   JSR  Print_CR
          JSR  wedge_dos_monitor
-         JSR  Print_CR
          JMP  Main