Module ; TRAP.ACT

;Use this routine to trap errors like
;Basic. Where ever you want the program
;to return to in your program just 
;call Trap. In your error checking 
;call Trap_Return and it will return
;to where Trap is located.
;Written by Joe Lesko          


  Byte S_P,Jmp_L,Jmp_H
  Byte End
  Byte Counter=[0]

  Define
  STA="$8D",
  LDA="$AD",
  STX="$8E",
  LDX="$AE",
  TXS="$9A",
  TSX="$BA",
  PHA="$48",
  PLA="$68",
  RTS="$60" 



Proc Trap_Return()
  [
  LDX S_P
  TXS
  LDA Jmp_L
  PHA
  LDA Jmp_H
  PHA
  RTS]

Proc Trap()

  [
  PLA
  STA Jmp_H
  PLA
  STA Jmp_L
  TSX
  STX S_P
  PHA
  LDA Jmp_H
  PHA
  RTS]

Module

Proc MyError(Byte Err)

  End=0
  If Err=128 and Counter>=5 Then
    End=1
  Else
    Trap_return()
  Fi

Return

Proc Example()

  End=0
  Counter=0
  Error=MyError
  Trap()
  Counter==+1
  Position(2,5)
  PrintBE(Counter)
  Do
    Position(2,2)
    PrintE("Hit the [BREAK] and the Counter")
    PrintF("Value will be incremented and printed%E")
    If End=1 Then
      Exit
    Fi
  od

Return