#441 Enable DISCiPLE on 128K machines

[Sergio Baldoví]

Alan Pearson posted technical info to enable DISCiPLE on 128K machines:
https://sourceforge.net/p/fuse-emulator/mailman/message/58749701/

I've disabled the trap at 0x0001 and DISCiPLE seems to work on a 128K, at least with FORMAT and CAT commands, but I think we can do something clever to enable trap 0x0001 when the machine hasn't been reset.