Advanced Guide to ThinkDOS

Understanding the fundamentals of ThinkDOS will better allow you to understand how to fix things when someone messes up the station horribly, figure out how to send and observe network traffic, and use advanced programs.

Peripherals

When you construct your computer, you can fit up to 3 peripherals on the computer mainboard. One of these should always be an ID scanner module or you won't be able to even log into the computer. The ThinkDOS command periph view will tell you what peripherals you currently have installed, their slot number, and their status. Certain peripherals are capable of special commands. To issue a command, enter periph command # [blah], where # is the slot number and [blah] is what you want it to do.

ID Scanner Module

Necessary for logging into a computer.

• eject Ejects the card.
• checkaccess Checks the access level of the current card.

Floppy Drive Module

Adds a second floppy drive to the computer (default name sd0).

ROM Cart Reader Module

Allows the computer to read PDA CARTs. Bear in mind that you cannot directly run PDA programs on ThinkDOS as they are a different file extension.

Sound Synthesizer Module

• beep Beeps.
• speak sig Speaks [data] with the name [name] in a signal file.

Printer Module

• print file Prints a file, one at a time.

Prize Vending Module

• vend Pops out a random goody that could otherwise be won at the arcade. Takes about 45 seconds to recharge.

Limited Wireless Module

A wireless network card that is stuck at one frequency.

• ping Pings the network.

Wired Network Card

If the computer is on a valid data terminal, it will give the computer a numerical address and allow you to see and communicate with other devices on the same network. This is not limited to computers, for instance, the communications array is a device on the main network.

• ping Pings the network.
• transmit sig Transmits the specified signal file.

Wireless Network Card

A wireless card that allows the computer to send and receive on a specified radio frequency. There are many systems operating on many different frequencies, and you may need some experimentation to figure out what is what. A good starting point is 114.9, the frequency for PDA text message.

• ping Pings the network.
• mode_free Switches to free mode. The wireless card will pick up all radio traffic on its current frequency, whether or not it is specifically directed at the computer's network address. The card can also send packets without its sender ID. The trade-off is that the computer can only broadcast on a limited radius (about 8 tiles) in this mode.
• mode_net Switches to net mode. The wireless card will only receive traffic specifically addressed to it, and must specify its sender ID in outgoing packets. Its range is effectively infinite in this mode.
• # will set the wireless card to that frequency.
• transmit sig Transmits the specific signal file.

Signals: What It's All About

Almost all network traffic is in the form of signals. With the right tools, it is possible to intercept, craft, and forge your own signals. A typical signal might look like this:

[command] [text_message]
[message] [What is your favorite pony]
[sender_name] [Weedgoku420]
[address_1] [02001921]
[sender] [02002276]

Each line of the signal consists of two items, the first item identifying the type of data, the second item identifying the actual data. This packet can be broken down as such:

[command] [text_message]
This tells the PDA that this command is a text message. This is just one of many commands available.

[message] [What is your favorite pony]
This is the text of the message. Note that a computer can handle a maximum of 26 characters.

[sender_name] [Weedgoku420]
This is what the sender's name will appear as in the message. No verification of this is done whatsoever, so the PDA will happily display whatever is written in the signal file. The limitation is again 26 characters.

[address_1] [02001841]
This is the network ID of the PDA the message will be going to.

[sender] [02002872]
This is the network ID of the PDA sending the message.

SigCatcher

The best way to find signals to decipher is with the program SigCatcher, available on the Network Tools disk. SigCatcher will snag any packet that the computer can detect-- either wired packets sent directly to that computer, or wireless packets when the wireless card is in mode free. The program only has a buffer for one signal at a time though, so you may need to check it frequently. It can run as a program in the background while you mess with other things. SigCatcher has two modes:

• on will display the last packet received.
• auto will grab the first packet it receives, then stops monitoring traffic, ensuring the packet is not overwritten by subsequent network activity.
  
  
• save will save the current signal as a file to your computer.
• quit will get you out of the program, but keep it running in the background.
• fquit will end the program entirely.

SigCraft

Once you've started deciphering packets, you can begin to make your own using SigCraft.

• Add [Title] [Data] is the core to setting up your packets. You need to have the right titles for other machines to understand what you're sending them.
• Line [Line] & Remove If you make a mistake, you can't simply overwrite a line, you have to select it, delete it, then select the bottom line of your current packet.
• Save To save as a signal file.
• Recsave To save as a rec file, which can be reviewed using the read command.

Any packet you send must have both a sender ID and an address. In mode net and on wired networks, the sender ID must correspond to your network module's number-- you can check that using the periph view command. Other data can be spoofed-- for instance, in sending a text message, you could change the sender name to whatever you want and make security think the Captain is ordering them to start an anti-revolutionary massacre.

Other Programs

WizWrite

A primitive line by line text editor. Useful if you want to spam your seditious materials everywhere and can't be bothered to find a pen and paper.

FROG

Allows you to ping and connect to other terminals in a manner similar to DWAINE. Bear in mind that the Research Mainframe is on a physically separate network from the rest of the station. FROG will not recognize a wireless card.

Ping

Pings and records ping data. Also does not recognize a wireless card.

Other Equipment

Data Terminal

File:DataTerminal.png

This is the physical link to the wired network. A computer must be built on top of it to access that network. The most obvious and accessible data terminal is in Tech Storage, but many more can be found around the station, and they are under all of the existing ThinkDOS computers. The mechanics can make more, but must be able to properly wire them to the network.

Packet Sniffer

Found in Tech Storage. Capable of detecting all packets sent on the wired network it is attached to. Looks and functions like a powersink-- just screw it onto a data terminal and it will begin scanning. There is not much data on the main network of the station besides that which comes from the communications dish, but other interesting data may be found by setting up the sniffer on the Engineer or Research networks.

Network Diagnostics Cart

This cart can accomplish many of the same tasks as the network tools disk, but from your PDA. It features a ping tool, a packet sniffing tool, a packet sender, and a packet crafting tool. The range on the packet sniffer can be adjusted from close to far. The packet crafting tool does not have the 26 character string limit that SigCraft does, allowing more complicated messaging.

CompTech

The vending machine in tech storage, which dispenses much of the equipment needed to build ThinkDOS computers. When hacked, will also provide prize vending modules and wireless modules.