Forth Commands

Forth has a very simple command structure. Forth commands, also called Forth words, consist of any combination of characters that can be printed--for example, letters, digits, or punctuation marks. Examples of legitimate words are shown below:

@

dump

.

0<

+

probe-pci

To be recognized as commands, Forth words must be separated by one or more spaces (blanks). Pressing Return at the end of any command line executes the typed commands. (In all the examples shown, a Return at the end of the line is assumed.)

A command line can have more than one word. Multiple words on a line are executed one at a time, from left to right, in the order in which they were typed. For example:

ok testa testb testc 
ok 

is equivalent to:

ok testa 
ok testb 
ok testc 
ok 

In OpenBoot, uppercase and lowercase letters are equivalent. Therefore, testa, TESTA, and TesTa all invoke the same command. However, words are conventionally written in lowercase.

Some commands generate large amounts of output (for example, dump or words). You can interrupt such a command by pressing any key except q. (If you press q, the output is aborted, not suspended.) Once a command is interrupted, output is suspended and the following message appears:

More [<space>,<cr>,q] ? 

Press the space bar (<space>) to continue, press Return (<cr>) to output one more line and pause again, or type q to abort the command. When you are generating more than one page of output, the system automatically displays this prompt at the end of each page.