How to Use ToonTalk Extensions

How to Use ToonTalk Extensions

For advanced users only:

ToonTalk extensions are birds that can fly "outside" of ToonTalk to the operating system. You start off with only one "foreign" bird. But she can bring you a bird connected to any ToonTalk extension installed on your system. You can find her near the end of your sensor notebook. She has a question mark on her T-shirt. To "open" an extension, give her a box with 2 holes: the first should hold the name of the extension and the second another bird who will come back with a new bird (in a box). The kinds of messages (boxes), the new bird should be given depends upon which extension she flies to.

Any programmer who can make Windows DLLs (Dynamic Link Libraries) can make new extensions. Maybe over time programmers will add new extensions, for example, for generating music, or connecting to the Internet, or doing 3D graphics. Currently, there is only one extension that can be installed:

The FILE extension. This extension enables you to open files and read and write them. You should give a bird connected to this extension a box with 3 holes. The first hole should contain one of the message names listed below. The second hole should contain the name of the file you want. The third hole should contain a bird who will receive a box with another bird in it. This new bird will take messages to the file.

Create File.: If the first hole contains the words "create file", then a file will be created for you. The second hole should contain the name of the file you want to create. A file with that name should not already exist. The name should follow the file naming rules of the operating system.
Open.: If the first hole contains the word "open", then a file will be opened for you. The second hole should contain the name of a file that already exists. The file is opened using Windows CreateFile procedure. This means the name can be the name of a file, pipe, mail slot, communications resource (e.g. "LPT1" or "COM1"), disk device, console, or directory to open.
Open Serial Port.: If the first hole contains the words "open serial port", then a serial port will be opened with the characteristics specified in the name found in the second hole. For example, if the second hole contains "COM1: baud=1200 parity=N data=8 stop=1" then the serial port number one of your computer will be opened with a 1200 baud rate, with parity off, 8 bit data, and stop equal to 1. This feature relies upon Windows BuildCommDCB procedure to interpret port descriptions.

Messages to Files. After you successfully opened or created a file, you should have a bird that flies to that file. She should have the file name on her T-shirt. You can give her a message with 3 holes. The first hole can be any of the message names listed below. The proper contents of the second hole depend upon the first. The third hole should contain a bird who will receive a reply.

Read.: The second hole should contain a number that says how many letters or characters to read. The bird is given a text pad with the letters read. If the end of the file was reached, then the number of letters will be less.
Write.: The second hole should contain a text pad to add to the file. The bird is given a number pad that shows the number of letters actually added to the file.
Read Bytes.: The second hole should contain a number that says how many letters or characters to read. The bird is given a box with a hole for each character read. Inside each hole is the ASCII number for the character. If the end of the file was reached, then the number of letters will be less.
Write Bytes.: The second hole should contain a box with a hole for each byte to add to the file. Each hole should contain a number between 0 and 255. If a number is too large only the low order byte will be written. You can use the ASCII encoding of characters here. The bird is given a number pad that shows the number of letters actually added to the file.

The ability to read and write bytes is particularly important when dealing with serial or parallel communication ports.