; A device raising its line with nothing installed to answer it, CAUGHT.
;
; The other half of the fault that could not be handed over. A program that asks a device to
; interrupt it and then forgets the handler used to stop the machine dead; now it goes to a
; vector of its own with the port in Q, so the program can say which device it was that
; nobody was listening to.
;
; NOTHING IS TYPED AT THIS. The console raises its line once at the end of input as well as
; for an arriving byte - which is exactly so that a program driven by interrupts is told when
; nothing more is coming - and the test is run with no input at all, so that end is what
; arrives.
;
; Correct output is:
;   nobody listening on port 00
;   and a clean halt.

#Include console.asm

#Program

start:
  INIA 0x02                 ; Interrupt when the console has something to say.
  OUTA 0x02
  SIF
spin:
  ; Never touches the console. Whatever happens below is something that interrupted this.
  BRI spin

; Q holds the port whose entry was empty. The console is port zero.
nobody:
  SETD.0 NobodyText
  CALL printString
  MVQA
  CALL printByteHex
  CALL newLine

  ; The console back to how it was found, so nothing else is asked for, and stop. There is
  ; nothing to resume to: the loop above only exists to be interrupted.
  RSTA
  OUTA 0x02
  HALT

#Data

NobodyText:
"nobody listening on port "

#Vectors

  Boot     start
  NoDevice nobody