User Manual |

8. Using the serial port |

Contents of this page |

8.1 Introduction 8.2 Configuring the serial port 8.3 Connecting the serial port 8.4 Connecting to Enigma-E (forthcoming product)

8.1 Introduction |

From version 1.30 onwards, a new feature has been added to allow communication through the serial port of your computer. This way messages can be sent out, e.g. to another computer running !Enigma. A simple ASCII protocol is used, so that you can connect a simple terminal at the other end to receive your encrypted text. Alternatively, you may type characters from the other end which will then be processed by Enigma. Two computers running !Enigma may be connected this way. Typing a message on one machine, will result in an encrypted messages being sent through the serial port. At the other end, the message will be decrypted and you'll be able to read your original message there... that is if the settings on both machines were the same!

8.2 Configuring the serial port |

The serial port is disabled by default to prevent clashes with other software, such as your Internet connection via a modem. If you want to use the serial port, you'll first need to turn it on. To do this, select Choices... from the iconbar menu and select the 4th TAB Serial port settings. The first switch in this window is used to enable/disable the serial port for Enigma. To use the port, turn this option on. Next you need to setup which serial port you want to use. If you are running on a standard Acorn computer, with no additional hardware, you'll probably only have the standard internal serial port available for use. In that case, use the default driver for the internal port, called InternalPC. Users of a 32-bit RISC OS will have to use Internal32. If you are running on an older system (e.g. an Archimedes) you may have to use the alternative driver Internal when using old-type wiring. |  |

By default, the serial port is configured to run at 9600 baud, a data format of 8N1 and no handshaking. This is done to allow connection to a forthcoming product (see below). You may alter the serial settings, by clicking the Setup button to the right of the Interface field. Buffer size/ The size of both the input and output buffer is set to 4096 bytes each. This will be sufficient in most cases, but it may be adjusted if needed. The buffer size will only be adjusted if this is allowed by the serial driver in use. The middle section of the window controls the input of data via the serial port, i.e. the reception of a message. The options have the following meaning: Allow serial input This option is used to turn input on or off. When off, !Enigma will not read any data received on the serial port. When on data received over the serial port will be interpreted as if it was typed in on your keyboard. Reset on Escape Whe this option is on, reception of an Escape character will reset your Enigma to the current Grundstellung. All other special characters are ignored (except for A thru Z). Input focus When this option is on, serial input is only accepted if we have the input focus. This means that the title bar of either our main Enigma window or the Direct text window must be highlighted. This is particular useful when you are running multiple simulations, as only one program can use the serial port. Key delay When you are receiving information via the serial port, you may need some time to write down each letter as and when the lamp is lit. By default the lamp stays on for half a second, but you may want to increase this value allow more time to find the illuminated letter. The bottom section of the window controls the output of data via the serial port, i.e. the transmission of a message. The options have the following meaning: Allow serial output This option can be used to turn serial output on or off. When off, !Enigma will not send any data over the serial port when a key is pressed. When on, each time a key is pressed, the encryption of that letter is sent through the serial port. Send Escape to reset This option allow an Escape character to be sent whenever you reset your Enigma. If two machines are connected this way, and both machines have this option turned on, it might help to keep the machines synchronised.

8.3 Connecting the serial port |

Once the serial port has been configured as described in the previous section, you are ready to connect to an external device. When researching the Enigma encryption principles, it may be useful to connect an ASCII terminal at the other end. This can be another RISC OS computer, running a terminal emulator, or a completely different PC running terminal emulation (e.g. a Windows PC running Hyper Terminal). Alternatievely, you may connect another RISC OS computer running !Enigma at the other end, so that you can encrypt and decrypt messages in one go. To connect another machine to the serial port, you may use any standard RS232 cable. If the cable is fully populated (i.e. all wires are used), you may want to enable handshaking. The default settings however, is without handshaking so that a very simple cable, with only three wires, can be used. The pinout for such as simple cable is as follows:

Computer pinout | Signal | External device pinout
2 | TX data | 3
3 | RX data | 2
5 | Ground | 5

8.4 Connecting to Enigma-E (forthcoming product) |

We are currently working on an electronic variant of the famous Enigma machine, which will be called Enigma-E. This will be a stand-alone device that will behave like an Enigma M3 or M4. The device will be based on a microcontroller and will have LED displays instead of mechanical wheels. Furthermore it will feature a real Steckerbrett and a keyboard. Optionally, a serial port connector can be fitted to allow connection to another Enigma-E or... your RISC OS computer. Here are some teasers:

|  | The Enigma-E will be made available as a DIY kit, consisting of a PCB and all electronic components needed to build it. Full manual, instructions, etc. If you are iterested, please drop us an e-mail at enigma@xat.nl

© Copyright Paul Reuvers. Last changed: Mon,18 Aug 2003.08:27:56